Update changelog

README: various edits

Revert "Highlight block codes in Monokai color scheme"

This reverts commit 4525115.

Add a sample file for fenced code blocks

It will be used for screenshot purposes.

Fix a small bug in macro

Fix header indentation in the symbol list (Fixes SublimeText-Markdown…

…#150)

Merge branch 'v2.0.5'

Merge branch 'v2.0.4'

Highlight plain URIs and emails

Improve README