docs: install the site packages for contributors

The contributor install line left out mkdocs-material and
pymdown-extensions, so pipeline step 8b (render site) was skipped.
The ranges are the ones deploy-site.yml installs, and a test reads
them from the workflow.

CONTRIBUTING.md

@@ -46,7 +46,8 @@ Full walkthrough: [profiling guide](https://abdess.github.io/retrobios/wiki/prof
 The checks CI runs on a pull request (Python 3.12 or newer):
 
 ```bash
-pip install pyyaml "jsonschema[format-nongpl]" markdown
+pip install pyyaml "jsonschema[format-nongpl]" markdown \
+    "mkdocs-material>=9.7.5,<10" "pymdown-extensions>=10.14"
 python scripts/validate_pr.py --changed          # the BIOS files the branch adds
 python scripts/validate_schemas.py --source-only # profiles and platform files
 python scripts/profile_sync.py --changed --strict  # each profile the branch adds or edits

scripts/generate_readme.py

@@ -754,7 +754,8 @@ Full walkthrough: [profiling guide]({link("wiki/profiling")}).
 The checks CI runs on a pull request (Python 3.12 or newer):
 
 ```bash
-pip install pyyaml "jsonschema[format-nongpl]" markdown
+pip install pyyaml "jsonschema[format-nongpl]" markdown \\
+    "mkdocs-material>=9.7.5,<10" "pymdown-extensions>=10.14"
 python scripts/validate_pr.py --changed          # the BIOS files the branch adds
 python scripts/validate_schemas.py --source-only # profiles and platform files
 python scripts/profile_sync.py --changed --strict  # each profile the branch adds or edits

tests/test_contributing_text.py

@@ -70,6 +70,18 @@ class BeforeOpeningAPullRequest(unittest.TestCase):
         workflow = (REPO_ROOT / ".github" / "workflows" / "validate.yml").read_text(encoding="utf-8")
         self.assertIn("validate_schemas.py --source-only", workflow)
 
+    def test_it_installs_the_packages_the_site_render_needs(self):
+        """Without mkdocs-material and pymdown-extensions the pipeline's
+        render step (8b) is skipped for every contributor."""
+        deploy = (REPO_ROOT / ".github" / "workflows" / "deploy-site.yml").read_text(
+            encoding="utf-8"
+        )
+        specs = re.findall(r'"((?:mkdocs-material|pymdown-extensions)[^"]*)"', deploy)
+        self.assertEqual(len(specs), 2)
+        text = generate_readme.generate_contributing()
+        for spec in specs:
+            self.assertIn(f'"{spec}"', text)
+
 
 if __name__ == "__main__":
     unittest.main()