Refactor TAG ENV PR QA workflow

[guidemetothemoon]

• Moved all QA checks (linting, spelling, links) to GitHub Actions and cleaned up respective scripts, Makefile, etc. GitHub Actions are the 1-1 mapping of the original tool, i.e. either is from the same author or is referenced by the author to use when you want to run the respective tool as a GH Action. All actions run only for modified files, if there are any;
• Fixed a bunch of dead/broken links and spelling errors;
• Since cSpell hasn't worked for a while it raised a bunch of errors - improved the way it runs validations by adding custom TAG ENV dictionary with words to ignore, as well as patterns like code blocks in Markdown that we can ignore;
• Improved link check configuration and fixed findings from it;
• Added script and NPM command to install and run all the checks locally;
• Updated documentation to provide more information about QA checks we're running, how to run those locally and how to follow-up on detected issues;

Closes #156 #165

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[leonardpahlke]

cc

[leonardpahlke]

💙 LGTM

[leonardpahlke]

@chalin is this something you are interested in? 😃 (maybe this can serve as a template to restructure some other similar repos)

[guidemetothemoon]

@leonardpahlke are we OK to merge this PR or shall I wait a bit more for feedback? 😊

[chalin]

@chalin is this something you are interested in? 😃 (maybe this can serve as a template to restructure some other similar repos)

Maybe! Will take a look as soon as I can, but it'll likely be 24Q1 or 2 🤷🏼‍♂️