Use raw URL in contrib page too

Author: chalin

site/src/content/docs/getting-started/contribute.mdx

@@ -56,7 +56,7 @@ Running our documentation locally requires the use of Astro. Astro is a modern s
 
 1. Run through the [tooling setup](#tooling-setup) above to install all dependencies.
 2. From the root `/bootstrap` directory, run `npm run docs-serve` in the command line.
-3. Open `http://localhost:9001/` in your browser, and voilà.
+3. Open http://localhost:9001 in your browser, and voilà.
 
 Learn more about using Astro by reading its [documentation](https://docs.astro.build/en/getting-started/).