GitLab

* Updates the default branch from master to main

* Links from `master` to `main`

* Typo

* Update examples/flax/README.md
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* Support PEP 563 for HfArgumentParser

* Fix issues for Python 3.6

* Add test for string literal annotation for HfArgumentParser

* Remove wrong comment

* Fix typo

* Improve code readability
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* Use `isinstance` to compare types to pass quality check

* Fix style
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* Per-folder tests reorganization
Co-authored-by: sgugger <sylvain.gugger@gmail.com>
Co-authored-by: Stas Bekman <stas@stason.org>