See http://editorconfig.org/. Inspired by similar commit in universal-ctags.
The main reason why this might be interesting is that github understands it and shows correct tab sizes e.g. in pull requests. You can view, comment on, or merge this pull request online at:
https://github.com/geany/geany/pull/1193
-- Commit Summary --
* Add .editorconfig
-- File Changes --
A .editorconfig (11)
-- Patch Links --
https://github.com/geany/geany/pull/1193.patch https://github.com/geany/geany/pull/1193.diff