* ale.txt: fix indentation
* ale.txt: fix Type and Default markup
* ale.txt: use `not set` instead of `undefined`
This matches the way the variables are referenced in prose about
existence state.
* Add kotlin languageserver linter definition
* Added kotlin languageserver references in docs, fix missing !! on other linters
* Added Vader tests for root path detection in Kotlin Language Server
* Add ktlint support (without formatting) for kotlin filetype
* Fix code style and refactor to use ALE utility functions (GetMatches)
* Remove options for configuration file
* Refactor: Rename exec variable and use ale#Set for variable configuration