doc: restructure module rendering (#1083)

docs/src/modules.md

@@ -157,10 +157,30 @@ directly from `config`. See the reference pages for a list of options.
 Metadata is stored in `/modules/«module»/meta.nix`. The following attributes are
 available under `meta`:
 
-- `maintainers`: required list of maintainers. See [Maintainers](#maintainers)
-section.
 - `name`: required human-readable string name.
 
+- `homepage`: homepage string or attribute set of homepage strings, depending
+  on the number of homepages:
+
+  - ```nix
+    homepage = "https://github.com/danth/stylix";
+    ```
+
+  - ```nix
+    homepage = {
+      Nix = "https://github.com/NixOS/nix";
+      Nixpkgs = "https://github.com/NixOS/nixpkgs";
+    };
+    ```
+
+  The attribute names are used as hyperlink text and the attribute values are
+  used as URLs.
+
+- `maintainers`: required list of maintainers. See [Maintainers](#maintainers)
+  section.
+
+- `description`: optional markdown string for extra documentation.
+
 ### Maintainers
 
 New modules must have at least one maintainer.