Our team recently switched to using our very own system (yes, we use the docs.microsoft.com infrastructure internally too) to write technical specs – content is on GitHub and Markdown-based. Once we get the commit, the only thing we need to check is whether the file was added (at this time, I skipped retroactive addition of review items to existing specs), placed in the target directory and is a Markdown file (specs are only .md). The last step is updating the file itself, and that is done by pulling the content, adding an extra line that points to the issue (GitHub API will return the issue URL) at the very end of the file, encoding it back into a Base64 string and committing it into the repo.