feat: more formatters

[barrettruth]

Add some more formatters.

Did not write tests (yet?) but obviously tested the formatters themselves.

Also, sql-formatter doesn't seem to work with stdin = true (although it does work with null-ls as shown here). Had to resort to the config I wrote which edits in-place (which should be fine).

[barrettruth]

Can you add how to run tests to the documentation for contributing? I only have a little experience with busted.

[glepnir]

Testing these tools is a bit troublesome. Need curl or wget to install them and add to environment variables. Then write some test cases . but the priority is lower. can write a general helper to complete these operations in the future

[barrettruth]

Ok. May work on that in coming days.

[glepnir]

could you add them into readme

[barrettruth]

done

[barrettruth]

Should I just add as many sources from null-ls builtin formatters as possible until a way to figure out testing is discovered?

null-ls itself doesn't even test for formatting but it does for diagnostics - I think the latter is complex as you stated.

[glepnir]

I think it needs to be kept simple enough. Necessary for very common additions to builtins. For something rare I think it's better to add in local config. Avoid plugin bloat.

[glepnir]

good enough now. thanks