meta: add a section on AI-assisted PRs in CONTRIBUTING guide (#11388)

CONTRIBUTING.md

@@ -82,7 +82,7 @@ Apart from the `good first issue`, the following labels are also worth looking a
 - [`help wanted`](https://github.com/facebook/docusaurus/labels/help%20wanted): if you have specific knowledge in one domain, working on these issues can make your expertise shine.
 - [`status: accepting pr`](https://github.com/facebook/docusaurus/labels/status%3A%20accepting%20pr): community contributors can feel free to claim any of these.
 
-If you want to work on any of these issues, just drop a message saying "I'd like to work on this", and we will assign the issue to you and update the issue's status as "claimed". **You are expected to send a pull request within seven days** after that, so we can still delegate the issue to someone else if you are unavailable.
+If you want to work on any of these issues, just drop a message saying "I am working on this". **You do not need to ask for assignment to work on any issue explicitly marked as welcoming external contributions.** However, don't "cookie lick", or squat on an issue without actually sending a PR. You are automatically considered as giving up if you don't **send a PR within seven days after your comment**, and the issue automatically becomes up for grabs again.
 
 Alternatively, when opening an issue, you can also click the "self service" checkbox to indicate that you'd like to work on the issue yourself, which will also make us see the issue as "claimed".
 
@@ -214,6 +214,16 @@ After you have signed the CLA, the CLA bot would automatically update the PR sta
 
 If it happens that you were unavailable and your PR gets closed, feel free to reopen once it's ready! We are still happy to review it, help you complete it, and eventually merge it.
 
+### AI-assisted PRs
+
+We welcome the use of AI tools for authoring PRs, and we love to see people pushing the boundaries of AI capabilities. The core team actively uses different AI tools in our development process. However, we are aware that **many people are sending entirely AI-generated PRs as a low-effort way to farm OSS contributions**, so please be mindful of the following etiquette to show your respect for our time and our codebase:
+
+- **Be transparent**: If a significant portion of your code is AI generated, please indicate that in your PR description.
+- **Be accountable**: You are responsible for the code you submit, regardless of whether it was generated by AI or written by you. You should be able to explain every line of the code, ensure all tests pass, and address our reviews.
+- **Be reasonable**: Sometimes we receive 1k LOC PRs that are obviously AI-generated and implement unsolicited features. Please note that significant changes require prior communication and approval from the team in the form of an issue.
+
+We retain the right to close any PR that we deem as unproductive or low-effort, even when we agree with the spirit of the change.
+
 ### Breaking Changes
 
 When adding a new breaking change, follow this template in your pull request:
@@ -227,6 +237,10 @@ When adding a new breaking change, follow this template in your pull request:
 - **Severity (number of people affected x effort)**:
 ```
 
+> [!NOTE]
+>
+> Breaking changes should be discussed in the issue tracker before being implemented.
+
 ### What Happens Next?
 
 The core Docusaurus team will be monitoring pull requests. Do help us by keeping pull requests consistent by following the guidelines above.