marp-team · yhatt · Nov 6, 2018 · Nov 6, 2018 · Nov 6, 2018 · Nov 6, 2018
diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
@@ -0,0 +1,31 @@
+# Contributing to Marp core
+
+Thank you for taking the time to read how to contribute to Marp core! This is the guideline for contributing to Marp core.
+
+But this document hardly has contents! We are following [the contributing guideline of marp-team projects](https://github.com/marp-team/marp/blob/master/.github/CONTRIBUTING.md). Please read these guidelines this before starting work in marp-core.
+
+- [**Code of Conduct**](https://github.com/marp-team/marp/blob/master/.github/CODE_OF_CONDUCT.md)
+- [**Report issue**](https://github.com/marp-team/marp/blob/master/.github/CONTRIBUTING.md#report-issue)
+- [**Pull request**](https://github.com/marp-team/marp/blob/master/.github/CONTRIBUTING.md#pull-request)
+- [**Release**](https://github.com/marp-team/marp/blob/master/.github/CONTRIBUTING.md#release)
+
+## Development
+
+```bash
+# Build
+yarn build
+
+# Watch
+yarn watch
+
+# Output type definitions
+yarn types
+```
+
+### Official theme
+
+Marp core has some built-in official themes in `themes` folder. They should load when Marp class is initialized.
+
+#### Requirements
+
+- All of built-in theme have to support `invert` class. It provides an inverted color scheme from default color. Please also see [yhatt/marp#77](https://github.com/yhatt/marp/issues/77).
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,10 @@
 
 - No longer work with Node v6.14.2 and v6.14.3 ([#45](https://github.com/marp-team/marp-core/pull/45))
 
+### Added
+
+- Ready to allow contributing by adding [guideline for marp-core](./.github/CONTRIBUTING.md) ([#46](https://github.com/marp-team/marp-core/pull/46))
+
 ### Fixed
 
 - Force reflow on updated fitting elements in Edge ([#43](https://github.com/marp-team/marp-core/pull/43))

diff --git a/README.md b/README.md
@@ -9,8 +9,6 @@
 
 In order to use on Marp tools, we have extended from the slide deck framework **[Marpit](https://github.com/marp-team/marpit)**. You can use the practical Markdown syntax, advanced features, and official themes.
 
-### :warning: _marp-core is under construction and not ready to use._
-
 ## Basic usage
 
 We provide `Marp` class, that is inherited from [Marpit](https://github.com/marp-team/marpit).
@@ -68,6 +66,17 @@ Marp Markdown is based on [Marpit](https://github.com/marp-team/marpit) and [Com
   - Line breaks in paragraph will convert to `<br>` tag.
   - Auto convert URL like text into hyperlink.
 
+### [Built-in official themes][themes]
+
+We provide bulit-in official themes for Marp. See more details in [themes].
+
+|                Default                |                 Gaia                  |                Uncover                |
+| :-----------------------------------: | :-----------------------------------: | :-----------------------------------: |
+| [![](https://bit.ly/2Op7Bp6)][themes] | [![](https://bit.ly/2QhDq4S)][themes] | [![](https://bit.ly/2DqZvvh)][themes] |
+|       `<!-- theme: default -->`       |        `<!-- theme: gaia -->`         |       `<!-- theme: uncover -->`       |
+
+[themes]: ./themes/
+
 ### Emoji support
 
 Emoji shortcode (like `:smile:`) and Unicode emoji 😄 will convert into the SVG vector image provided by [twemoji](https://github.com/twitter/twemoji) <img src="https://twemoji.maxcdn.com/2/svg/1f604.svg" alt="😄" width="16" height="16" />. It could render emoji with high resolution.
@@ -228,7 +237,9 @@ You can modify KaTeX further settings by passing an object of sub-options.
 
   - By default, marp-core will use [online web-font resources through jsDelivr CDN](https://cdn.jsdelivr.net/npm/katex@latest/dist/fonts/). You have to set path to fonts directory if you want to use local resources. If you set `false`, we will not manipulate the path (Use KaTeX's original path: `fonts/KaTeX_***-***.woff2`).
 
-<!-- ## [Work in progress] Themes -->
+## Contributing
+
+Are you interested in contributing? Please see [CONTRIBUTING.md](.github/CONTRIBUTING.md).
 
 ## Author
 
@@ -238,4 +249,4 @@ Managed by [@marp-team](https://github.com/marp-team).
 
 ## License
 
-[MIT License](LICENSE)
+This package releases under the [MIT License](LICENSE).
diff --git a/themes/README.md b/themes/README.md
@@ -0,0 +1,85 @@
+# Marp-core built-in themes
+
+We provide some nice official themes in marp-core. You can choose a favorite theme by using [Marpit `theme` directive](https://marpit.marp.app/directives?id=theme) in your Markdown.
+
+Screenshots were taken from the rendered result of [an example][example].
+
+[example]: example.md
+
+### `invert` class
+
+The all of built-in themes support `invert` class to use the inverted color scheme.
+
+```markdown
+<!-- class: invert -->
+```
+
+## Default
+
+[![](https://user-images.githubusercontent.com/3993388/48039490-53be1b80-e1b8-11e8-8179-0e6c11d285e2.png)][example]
+[![invert](https://user-images.githubusercontent.com/3993388/48039492-5456b200-e1b8-11e8-9975-c9e4029d9036.png)][example]
+
+The default theme of Marp. It is based on [GitHub markdown style](https://github.com/sindresorhus/github-markdown-css), but optimized to the slide deck. Slide contents will be always vertically centered.
+
+```markdown
+<!-- theme: default -->
+```
+
+## Gaia
+
+[![](https://user-images.githubusercontent.com/3993388/48039493-5456b200-e1b8-11e8-9c49-dd5d66d76c0d.png)][example]
+[![invert](https://user-images.githubusercontent.com/3993388/48039494-5456b200-e1b8-11e8-8bb5-f4a250e902e1.png)][example]
+
+Gaia theme is based on the classic design of [yhatt/marp](https://github.com/yhatt/marp).
+
+Originally, this theme was created for a maintainer to use, and it's inspired from [azusa-colors](https://github.com/sanographix/azusa-colors/) keynote template.
+
+```markdown
+<!-- theme: gaia -->
+```
+
+### Features
+
+#### `lead` class
+
+![lead](https://user-images.githubusercontent.com/3993388/48040058-c62ffb00-e1ba-11e8-876d-c182a30714c6.png)
+
+Contents of the slide will align to left-top by Gaia's default. But you can use `lead` class to be centering like [uncover theme](#uncover). It is useful for the leading page like a title slide.
+
+```markdown
+<!--
+theme: gaia
+class: lead
+-->
+```
+
+> :information_source: Marpit's [Spot directive](https://marpit.marp.app/directives?id=apply-to-a-single-page-spot-directives) would be useful to apply `lead` class only into a current page.
+>
+> ```markdown
+> <!-- _class: lead -->
+> ```
+
+#### Color scheme
+
+![gaia](https://user-images.githubusercontent.com/3993388/48040059-c62ffb00-e1ba-11e8-8026-fa3511844ec7.png)
+
+Gaia theme supports an additional color scheme by `gaia` class.
+
+```markdown
+<!-- class: gaia -->
+```
+
+## Uncover
+
+[![](https://user-images.githubusercontent.com/3993388/48039495-5456b200-e1b8-11e8-8c82-ca7f7842b34d.png)][example]
+[![invert](https://user-images.githubusercontent.com/3993388/48039496-54ef4880-e1b8-11e8-9c22-f3309b101e3c.png)][example]
+
+Uncover theme has three design concepts: simple, minimal, and modern. It's inspired from many slide deck frameworks, especially [reveal.js](https://revealjs.com/).
+
+```markdown
+<!-- theme: uncover -->
+```
+
+### :warning: Restrictions
+
+[Auto scaling for code block](https://github.com/marp-team/marp-core#auto-scaling-features) is disabled because uncover theme uses the elastic style that has not compatible with it.
diff --git a/themes/example.md b/themes/example.md
@@ -0,0 +1,12 @@
+---
+theme: default
+class:
+---
+
+# marp-core
+
+The core of Marp converter
+
+###### Created by [marp-team](https://github.com/marp-team/)
+
+![bg right 50%](https://github.com/marp-team.png)