Add CHANGELOG
Raise a 404 when there's no blog.

This avoid to display an empty page for a tag that doesn't have any
blog.

(cherry picked from commit 605f90e19af70692c8f2f60d91642a1916170be3)
Only fetch tags that have published blogs

(cherry picked from commit da687079995497d8188f0fccbc041e23809ebb1c)
Release v1.0.1