Convert docstrings of modeling files (#14850)
* Convert file_utils docstrings to Markdown
* Test on BERT
* Return block indent
* Temporarily disable doc styler
* Remove from quality checks as well
* Remove doc styler mess
* Remove check from circleCI
* Fix typo
* Convert file_utils docstrings to Markdown
* Test on BERT
* Return block indent
* Temporarily disable doc styler
* Remove from quality checks as well
* Remove doc styler mess
* Remove check from circleCI
* Fix typo
* Let's go on all other model files
* Add templates too
* Styling and quality