I just submitted my first patch, and it was not entirely straightforward to follow the "Contributing" guide.

By chance, I discovered:

• There is also an HTTPS link available for submitting patches.
• You have to create a Gerrit user, and create credentials in the settings to submit a patch.
• You can generate a Change-Id however you like.

These could go into the guide to make things clearer for new users.

PR: https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/4517