committers-guide: update commit trailer descriptions

[emaste]

Summary

• Add Reported by, Tested by, Fixes, MFH.
• Mention that Submitted by is typically not used with git.
• Add more cases to Approved by.
• Move Sponsored by: to the same place it appears in the template.

[debdrup]

Just one small thing, and as long as it builds (which it should, from the looks of it), it looks good to me.

documentation/content/en/articles/committers-guide/_index.adoc

1649–1650

I think there should be some mention of the rules for this field, as I'm not entirely sure they're documented elsewhere, and it seems like a good place for the canonical definition, ie:

Hash length (lwhsu in D28881 mentioned git rev-parse --short for generating the shortest identifiable hash), and how titles can either be truncated or pushed onto a new line.

[debdrup]

I forgot to accept this, didn't I.

I know you'll fix these before you push it, though. :)

[emaste]

and as long as it builds

As an aside, checking this is so much nicer with asciidoc/hugo.