add yarn lockfile section for contributors (calcom#11769)

Co-authored-by: Peer Richelsen <[email protected]>

CONTRIBUTING.md

@@ -161,3 +161,48 @@ If you get errors, be sure to fix them before committing.
 - If your PR refers to or fixes an issue, be sure to add `refs #XXX` or `fixes #XXX` to the PR description. Replacing `XXX` with the respective issue number. See more about [Linking a pull request to an issue](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue).
 - Be sure to fill the PR Template accordingly.
 - Review [App Contribution Guidelines](./packages/app-store/CONTRIBUTING.md) when building integrations
+
+## Guidelines for committing yarn lockfile
+
+Do not commit your `yarn.lock` unless you've made changes to the `package.json`. If you've already committed `yarn.lock` unintentionally, follow these steps to undo:
+
+If your last commit has the `yarn.lock` file alongside other files and you only wish to uncommit the `yarn.lock`:
+   ```bash
+   git checkout HEAD~1 yarn.lock
+   git commit -m "Revert yarn.lock changes"
+   ```
+If you've pushed the commit with the `yarn.lock`:
+   1. Correct the commit locally using the above method.
+   2. Carefully force push:
+
+   ```bash
+   git push origin <your-branch-name> --force
+   ```
+
+If `yarn.lock` was committed a while ago and there have been several commits since, you can use the following steps to revert just the `yarn.lock` changes without impacting the subsequent changes:
+
+1. **Checkout a Previous Version**:
+   - Find the commit hash before the `yarn.lock` was unintentionally committed. You can do this by viewing the Git log:
+     ```bash
+     git log yarn.lock
+     ```
+   - Once you have identified the commit hash, use it to checkout the previous version of `yarn.lock`:
+     ```bash
+     git checkout <commit_hash> yarn.lock
+     ```
+
+2. **Commit the Reverted Version**:
+   - After checking out the previous version of the `yarn.lock`, commit this change:
+     ```bash
+     git commit -m "Revert yarn.lock to its state before unintended changes"
+     ```
+
+3. **Proceed with Caution**:
+   - If you need to push this change, first pull the latest changes from your remote branch to ensure you're not overwriting other recent changes:
+     ```bash
+     git pull origin <your-branch-name>
+     ```
+   - Then push the updated branch:
+     ```bash
+     git push origin <your-branch-name>
+     ```