Merge branch 'ss/clone-depth-single-doc' into maint

Documentation for "git fetch --depth" has been updated for clarity.

* ss/clone-depth-single-doc:
docs: clarify that --depth for git-fetch works with newly initialized repos
docs: say "commits" in the --depth option wording for git-clone
docs: clarify that passing --depth to git-clone implies --single-branch

diff --cc Documentation/fetch-options.txt
Simple merge

diff --cc Documentation/git-clone.txt
Simple merge