docs: Added section on signing off commits

[StandingPadAnimations]

This adds a section on signing off commits (noted to be optional, but useful), which is mostly a copy-paste of BpyBuild's section

To summarize: signing off commits is a way for the commit author to say, “Not only am I submitting this commit, the change made in this commit is allowed to be used”. This verifies:

• The person submitting the commit indeed made the change (what happens most of the time)
• The commit is based on existing code that is allowed to be used (ex. using code from another Blender addon, as all Blender addons are GPL licensed)
• The change in the commit comes from someone who has given permission for the change to be submitted (although they should also sign off of the commit). This includes coauthors.

As this is optional (although encouraged), this won't impact existing contributions to MCprep.

[TheDuckCow]

Getting to this now, for my understanding: is the difference here just a matter of adding additional text into one's commit? Or is this tied to some certificate setup (in which case, should we be linking to how to set that up)?

[StandingPadAnimations]

Getting to this now, for my understanding: is the difference here just a matter of adding additional text into one's commit? Or is this tied to some certificate setup (in which case, should we be linking to how to set that up)?

Yep, just adding additional text to the commit. git-commit also has the flag --signoff, which adds this automatically based on one's .gitconfig. Here's an example of how it would look in git-log

It's based on trust that the developer is actually following the rules laid out in the Developer's Certificate of Origin when they sign off (although for us here, while stated to be a good practice, signing off is optional, similar to our commit recommendations)

[TheDuckCow]

Got it, I think if we could include a link to some docs showing how to use the --signoff flag would be quite helpful for anyone trying to quickly understand this, myself included :)

[TheDuckCow]

Approving, presuming we'll add the context link showing how to use the signoff git flag

[StandingPadAnimations]

Done, I'll merge this in now