[clang-tools-extra] [clang-doc] add return comments to comment template (PR #150647)

[Aiden Grossman via cfe-commits]

boomanaiden154 wrote:

@evelez7 Do you have more details on what exactly you did within Graphite? Did you try to merge multiple PRs in a stack or just the bottom one?

https://github.com/llvm/llvm-project/pull/150647