feat: wire up INI files

tidy finds INI files by the plugin's names and extensions, but .pro
(mostly qmake) and .reg (UTF-16), and finds .npmrc too. .gitconfig,
.gitmodules and *.gitconfig use the git dialect. The CLI and the Node
binding take ini and gitconfig parsers, a config has an ini section
with spaceAroundEquals, and the shared indent, tabs and eol apply.
Markdown code blocks of INI format.

deviations.md lists where tidy differs from the plugin; the four
that the user hasn't seen yet are proposed.