Add automated linter; make PRs pass "mkdocs serve --strict"

[felker]

As mentioned in #64, we should consider adding a basic, automated linting step (perhaps in a pre-commit hook) to minimize commit noise and promote uniformity of style:

• deletes trailing whitespace
• converts DOS-style line endings to Unix-style
• check for broken links
• spelling and grammar, TensorFlow not tensorflow, etc. (although would take some time to build up a list of exceptions)

Some tools here: https://earthly.dev/blog/markdown-lint/, https://github.com/markdownlint/markdownlint/blob/master/docs/RULES.md

Would be simple to add Python-based linters to the venv already required to run mkdocs, then install a pre-commit hook with one line.

[bethcerny]

@felker who should this be assigned to?

[bethcerny]

I should say who is the TensorFlow SME? Taylor?

[felker]

I will fix TensorFlow stylization, but will table the automated linter discussion until there is more interest.

[felker]

mkdocs serve --strict GitHub Action would return an error code of 1 and print out:

...
WARNING  -  Documentation file 'ai-testbed/sambanova/running-bert-large-on-sn10-8r.md' contains a link to
            'ai-testbed/sambanova/bert/transformers_hook.py' which is not found in the documentation files.

Aborted with 10 warnings in strict mode!
make: *** [serve] Error 1

with the broken links warnings described in #162

[felker]

partially addressed by #246