Update matcha, nlcst-to-textom
Update parse-latin

This update makes it easier for plugins to hook into the NLCST
creation process: something that is useful for plugins which
add nodes or new structures (e.g., retext-emoji, retext-link).
Add flat badges to `Readme.md`
Remove personal intro from `Readme.md`
Add description of plugins to `Readme.md`
Add `logo.svg`
Refactor script targets in `package.json`
Update changelog for 0.4.0-rc.1
0.4.0-rc.1