Update textom, parse-latin

This updates the major dependencies to their latest stable
versions.
Refactor example in `Readme.md`

This changes the example to work with the new standard options,
available in retext-smartypants@0.4.0 and retext-emoji@0.3.0,
and retext@0.3.0-rc.2.
Update changelog for 0.3.0
0.3.0