ci: add linter for markdown, yaml, CSS, html

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 95.48%. Comparing base (937683f) to head (b73aa50). Report is 1 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #2176 +/- ## ======================================= Coverage 95.48% 95.48% ======================================= Files 18 18 Lines 1461 1462 +1 ======================================= + Hits 1395 1396 +1 Misses 66 66 ```

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