docs: add contributing guide (#2021)

* docs: add contributing guide

* Update apps/docs/pages/contributing.mdx

* Update apps/docs/pages/contributing.mdx

Co-authored-by: Bailey Pumfleet <pumfleet@hey.com>

apps/docs/pages/contributing.mdx

@@ -0,0 +1,83 @@
+---
+title: Contributing
+---
+
+# Contributing
+
+Contributions are what make the open source community such an amazing place to be learn, inspire, and create. Any contributions you make are **greatly appreciated**.
+
+- Before jumping into a PR be sure to search [existing PRs](https://github.com/calcom/cal.com/pulls) or [issues](https://github.com/calcom/cal.com/issues) for an open or closed item that relates to your submission.
+
+## Developing
+
+The development branch is `main`. This is the branch that all pull
+requests should be made against. The changes on the `main`
+branch are tagged into a release monthly.
+
+To develop locally:
+
+1. [Fork](https://help.github.com/articles/fork-a-repo/) this repository to your
+   own GitHub account and then
+   [clone](https://help.github.com/articles/cloning-a-repository/) it to your local device.
+2. Create a new branch:
+
+   ```sh
+   git checkout -b MY_BRANCH_NAME
+   ```
+
+3. Install yarn:
+
+   ```sh
+   npm install -g yarn
+   ```
+
+4. Install the dependencies with:
+
+   ```sh
+   yarn
+   ```
+
+5. Start developing and watch for code changes:
+
+   ```sh
+   yarn dev
+   ```
+
+## Building
+
+You can build the project with:
+
+```bash
+yarn build
+```
+
+Please be sure that you can make a full production build before pushing code.
+
+## Testing
+
+More info on how to add new tests coming soon.
+
+### Running tests
+
+This will run and test all flows in multiple Chromium windows to verify that no critical flow breaks:
+
+```sh
+yarn test-e2e
+```
+
+## Linting
+
+To check the formatting of your code:
+
+```sh
+yarn lint
+```
+
+If you get errors, be sure to fix them before comitting.
+
+## Making a Pull Request
+
+- Be sure to [check the "Allow edits from maintainers" option](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/allowing-changes-to-a-pull-request-branch-created-from-a-fork) while creating you PR.
+- 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. Se 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.

apps/docs/pages/meta.json

@@ -11,5 +11,6 @@
   "import": "Import",
   "billing": "Billing",
   "developer": "Developer",
+  "contributing": "Contributing",
   "faq": "FAQs"
 }