git has a way to run scripts, which are invoked by specific git commands.
The git hooks are located in `<mbed TLS root>/.git/hooks`, and as such are not under version control
for more information, see the [git documentation](https://git-scm.com/docs/githooks).
The mbed TLS git hooks are located in `<mbed TLS root>/git_hooks` directory, and one must create a soft link from `<mbed TLS root>/.git/hooks` to `<mbed TLS root>/git_hooks`, in order to make the hook scripts successfully work.