no bug - doc(import-mdn): Update the procedure as it didn't work archived pages r=firefox-source-docs-reviewers,championshuttler DONTBUILD

Differential Revision: https://phabricator.services.mozilla.com/D104992

tools/moztreedocs/docs/mdn-import.rst

@@ -4,25 +4,28 @@ Importing documentation from MDN
 As MDN should not be used for documenting mozilla-central specific code or process,
 the documentation should be migrated in this repository.
 
-Fortunatelly, there is an easy way to import the doc from MDN
+Fortunately, there is an easy way to import the doc from MDN using GitHub
 to the firefox source docs.
 
 1. Install https://pandoc.org/ - If you are using packages provided by your distribution,
    make sure that the version is not too old.
 
-2. Add a ``?raw=1`` add the end of the MDN URL
+2. Identify where your page is located on the GitHub repository ( https://github.com/mdn/archived-content/tree/main/files/en-us/mozilla ).
+   Get the raw URL
 
 3. Run pandoc the following way:
 
 .. code-block:: shell
 
-   $ pandoc -t rst https://wiki.developer.mozilla.org/docs/Web/JavaScript?raw\=1  > doc.rst
+   $ pandoc -t rst https://github.com/mdn/archived-content/tree/main/files/en-us/mozilla/firefox/performance_best_practices_for_firefox_fe_engineers > doc.rst
 
-4. Verify the rst syntax using `./mach lint -l rst`_
+4. In the new doc.rst, identify the images and wget/curl them into `img/`.
+
+5. Verify the rst syntax using `./mach lint -l rst`_
 
 .. _./mach lint -l rst: /tools/lint/linters/rstlinter.html
 
-5. If relevant, remove unbreakable spaces (rendered with a "!" on Phabricator)
+6. If relevant, remove unbreakable spaces (rendered with a "!" on Phabricator)
 
 .. code-block:: shell