Merge branch 'release/4.0.4'

Conflicts:
	README.md

Add note about Ruby gem version

Update CHANGELOG.md and bump version to 4.0.4

Merge branch 'feature/theme-gem' into develop

Add `_data` files to root for those forkers of the repo

Added missing Turkish translation for UI text (#621)

Added missing Turkish translation for UI text (#621)

Fix typo and update link to beta release post

Fix typo and update link to beta release post

Remove `prepend: "/"` from includes and add to image path's instead

Add default config and home index page

Fix navigation bar animation "flicker" in Safari
- Close #568

Bump version to 4.0.3

Add links to documentation

Rename LICENSE

Update README

Make author avatar optional

Add Jekyll v3.3 as dependency

Simplify example site's `Gemfile`

Add sample home page to example site