Add linting following styleguide

[TheTripleV]

Adds a linter package that extends doc8 to add tests for conformity to the stricter frc-docs styleguide.

Checks included:

• CheckFilenames
  • make sure filenames are valid
  • make sure directory names are valid
• CheckTermSpelling
  • make sure terms are spelled correctly
• CheckHeadingUnderscores
  • make sure headings are used in the correct order
  • make sure heading underline lengths are correct
• CheckDoubleNewlines
  • make sure there are no double newlines
• CheckTrademarks
  • make sure the first instance of some terms are trademarked
• CheckFIRSTItalicized
  • make sure FIRST is italicized
• CheckBlankLinkAfterHeader
  • make sure headers are followed by a blank line
• CheckBlankLinkAfterDirective
  • make sure directives without options are followed by a blank line
• CheckIndentation
  • make sure indents follow styleguide (todo: add list support done)
• CheckInteriorSpaces
  • make sure sentences only have 1 space separating them
• CheckImageAlt
  • make sure all images have alt text
• CheckSingleLineParagraph
  • make sure all paragraphs are on a single line

Testing

I wrote all the boilerplate required for testing.
Tests are welcome.

Future

This linter finds many issues in frc-docs. They should go in a separate PR once this one is finalized to reduce clutter.

[TheTripleV]

The styleguide needs to be excluded as it explicitly does not follow the styleguide.

[TheTripleV]

linter reports 3482 errors.

[Daltz333]

For right now, can it be added to run as diffs that way we can slowly migrate as things get updated.

[TheTripleV]

I think that should do it?

[sciencewhiz]

Does this exclude code?

[TheTripleV]

doc8 uses docutils directly so deleting code files shouldn't matter. Just in case, I changed it to only delete rst files.

[sciencewhiz]

I meant, for example, if a there's two consecutive new lines within a .. code:: directive, would this flag it?

[TheTripleV]

code directives are excluded from all checks except for the two consecutive lines test.

I had accounted for code-blocks and code-tabs but forgot about regular old code. I fixed that now.

[sciencewhiz]

Is there a way to disable a specific linter for a block?

[TheTripleV]

If you're asking if there are pre-processor flags of sort that allow users to disable linting for blocks, then no.

I think that any excluded blocks should be hardcoded into the checks.

[TheTripleV]

Removed the linter source and updated ci to use ohnoyoudidnt