docs: Add note about the bot opening PRs

CONTRIBUTING.md

@@ -4,15 +4,15 @@ Thank you for your contribution. Here are a set of guidelines for contributing t
 
 ## Version Updates
 
-New **Node.js** releases are released as soon as possible.
+New **Node.js** releases are released as soon as possible. Security and patch updates are automatically opened on this repository by the [nodejs-github-bot](https://github.com/nodejs-github-bot) once the `musl` builds are completed for all new versions on <https://unofficial-builds.nodejs.org/>.
 
 New **NPM** releases are not tracked. We simply use the NPM version bundled in the corresponding Node.js release.
 
 **Yarn** is updated to the latest version only when there is a new Node.js SemVer PATCH release (unless Yarn has received a security update), and it's updated only in the branch with the new release, preferably in the same PR. The `update.sh` script does this automatically when invoked with a specific branch, e.g. `./update.sh 6.10`.
 
 ### Submitting a PR for a version update
 
-If you'd like to help us by submitting a PR for a version update, please do the following:
+If you'd like to help us by submitting a PR for a new **major** version update, please do the following:
 
 1. [Fork this project.](https://docs.github.com/en/get-started/quickstart/fork-a-repo)
 1. [Clone the forked repository.](https://docs.github.com/en/github/creating-cloning-and-archiving-repositories/cloning-a-repository)