* initial commit

project structure
initial test cases
directly modify source to rename references

* code style

* enable for ghc < 8.8.0

* remove aeson from build-depends

* update support

support ghc9
revert retrie version bump
disable feature by default

* enable plugin for testing

* fix test.yml

* code style, ghc9 retrie bump

remove unnecessary flag in test.yml
consistent indentation
increase retrie version for ghc 9.0.1 (decreased by mistake)

* avoid using Data.List.nub

* code style

fix typo in indentation test
break lines at 100 chars
rename some vars

* code style / performance

remove Retire dependency by using exactprint directly
group references by file to increase speed of checking `elem` per file
add test cases (typeclass, let expression)
add some documentation
fix bug when looking up reference in HieDb
improve error messages
rename some function / vars

* replace GhcPlugins import with Name import

* use GHC.Types.Name for ghc >= 9.0.1