[DOCS] Fix broken "community" links across CONTRIBUTING.md

### Description
Multiple links pointing to the community forum throughout `CONTRIBUTING.md` rely on an invalid or broken URL path (`pipedream.com/community/...`), causing proxy errors when clicked.

### Steps to Reproduce
1. Open [`CONTRIBUTING.md`](https://github.com/PipedreamHQ/pipedream/blob/master/CONTRIBUTING.md).
2. Click on any of the **community** or **community forum** links across sections like **Ask & Answer Questions** or **Share Your Workflows**.
3. Observe the proxy error displayed on the resulting page.

### Expected Behavior
All community links should successfully redirect to the active [Pipedream community forum](https://pipedream.com/community).

### Actual Behavior
Clicking the links leads to a broken route with the following proxy error:
`Error occurred while trying to proxy: pipedream.com/community/c/dev/11`

### Additional Context
- **Affected File:** `CONTRIBUTING.md`
- **Affected Links:** All instances referencing the `pipedream.com/community/c/dev/...` path.

Open CONTRIBUTING.md and review every community or community forum link, especially those in the Ask & Answer Questions and Share Your Workflows sections. Verify that all affected links use the active Pipedream community forum and no longer lead to the broken /community/c/dev/... route.

Written by the indexing model from the issue text.