Documentation: Rework staging and commit information

This patch does two things:
- The CLI and Git Cola sections contained some duplicated information
  about pushing patches, which is now factored out into its own section.
- The draft workflow is now disabled, so that part has been reworded to
  describe how to submit a private patch.

Signed-off-by: David Hendricks <david.hendricks@gmail.com>
Change-Id: I562c101ab2ee78d901be7e99165daba7473dc3c1
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37256
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

Documentation/tutorial/part2.md

@@ -157,10 +157,10 @@ commit, you wish to make changes to it, running `git commit --amend` allows
 you to take back your commit and amend it.
 
 When you are done with your commit, run `git push` to push your commit to
-coreboot.org. **Note:** To submit as a draft, use
-`git push origin HEAD:refs/drafts/master`. Submitting as a draft means that
-your commit will be on coreboot.org, but is only visible to those you add
-as reviewers.
+coreboot.org. **Note:** To submit as a private patch, use
+`git push origin HEAD:refs/for/master%private`. Submitting as a private patch
+means that your commit will be on review.coreboot.org, but is only visible to
+yourself and those you add as reviewers.
 
 This has been a quick primer on how to submit a change to Gerrit for review
 using git. You may wish to review the [Gerrit code review workflow
@@ -227,9 +227,6 @@ explained in the extended description.
 
 When ready, select 'Commit' again. Once all errors have been satisfied
 and the commit succeeds, move to the command line and run `git push`.
-**Note:** To submit as a draft, use `git push origin HEAD:refs/drafts/master`.
-Submitting as a draft means that your commit will be on coreboot.org, but is
-only visible to those you add as reviewers.
 
 ## Part 5: Getting your commit reviewed