Link to local installation instructions in CONTRIBUTING.md

Author: kurahaupo

CONTRIBUTING.md

@@ -35,12 +35,12 @@ You can then [open a pull request][pr] on [the l10n repository][l10n].
 ## Tips for contributing
 
 1. Choose [an issue][issues] that you would like to work on.
-2. Fork the repository and follow the instructions for setting it up locally.
-3. Run the add-on locally and try reproducing the issue.
-4. Debug add-ons by clicking the “Settings” icon in about:addons, and then clicking “Debug Add-ons”
-5. Click “Inspect” on the MAC add-on to open developer tools for the popup extension (see [this documentation][extension-doc] for more information)
-6. Once you have a fix ready, commit your changes with the following commit message template: “Fix #<insert issue id #>: <short description>”
-7. Push your changes and open a pull request for review.
+2. Fork the repository and follow the [instructions for setting it up locally](https://extensionworkshop.com/documentation/develop/temporary-installation-in-firefox/).
+4. Run the add-on locally and try reproducing the issue.
+5. Debug add-ons by clicking the “Settings” icon in about:addons, and then clicking “Debug Add-ons”
+6. Click “Inspect” on the MAC add-on to open developer tools for the popup extension (see [this documentation][extension-doc] for more information)
+7. Once you have a fix ready, commit your changes with the following commit message template: “Fix #<insert issue id #>: <short description>”
+8. Push your changes and open a pull request for review.
 
 If you run into an issue, you can always ask the other community members in the [discussions board][discussions]. 
 
@@ -51,4 +51,4 @@ If you run into an issue, you can always ask the other community members in the
 [issues]: https://github.com/mozilla/multi-account-containers/issues
 [l10n]: https://github.com/mozilla-l10n/multi-account-containers-l10n/
 [pr]: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/about-pull-requests
-[web-ext]: https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Getting_started_with_web-ext
+[web-ext]: https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Getting_started_with_web-ext