fix: remove unused languages from codeeditor (#136)

* fix: remove unused languages from codeeditor

* remove @uiw/codemirror-extensions-langs: Extra languages were not
  accessible and only served to bloat build size when consuming apps
  import the code editor

* use new yaml languagesupport: the old yaml package and the one
  included in the extension module did not support code folding.

* reuse github flavored markdown instead of commonmark: github flavored
  markdown highlights regular links and tables.

* centralize language definitions