chktex is a LaTeX linter. A linter is a program that checks your work for stylistic errors. In the case of LaTeX, style errors include soft tex-O's (which don't generate errors) and decisions that result in rendering irregularities.
This action runs chktex on all .tex files in your repository.
To configure the linter, add a .chktexrc file to your repository. An example
is provided in this repo.