Bump version to 0.2.0

No longer requires recompilation of previews to update the Gallery (#2)

* Evaluates preview details during runtime

* Documents static gallery generation

* Better specs

* Replaces previews/0 and groups/0 by get/0

Co-authored-by: Vitor Cavalcanti <[email protected]>
Co-authored-by: Lucas Mazza <[email protected]>