* refactor(color): Use enum class for color type
* Add testcases for tag parser
* Make tag parser a pull-style parser
Being able to parse single elements at a time gives us more fine-grained
error messages, we can also parse as much as possible and only stop
after an exception.
* fix(color): Parser did not check for invalid chars
* tag parser: First full implementation
* tag parser: Fix remaining failing tests
* tag parser: Replace old parser
* tag parser: Treat alignment as formatting tag
Makes the structure less complex and the alignment tags really are
formatting tags, they are structurally no different from the %{R} tag.
* tag parser: Cleanup type definitions
All type definitions for tags now live in tags/types.hpp, the parser.hpp
only contains the definitions necessary for actually calling the parser,
this shouldn't be included in many places (only places that actually do
parsing). But many places need the definitions for the tags themselves.
* Rename components/parser to tags/dispatch
* tag parser: Cleanup
* Add changelog
* Adopt keep a changelog
Ref: https://keepachangelog.com/en/1.0.0/
* Add changelog to release and contributing docs
* Use H2 for automatically added Download section
The individual changelog subsections use H3 and the changelog section
uses H2, so the Download section should use the same heading
* Add already present changes to changelog
* Mention changelog issue references in CONTRIBUTING.md
