Fixes function searching and jumping (#389)

- Reworks how function names are rendered on the functions page, meaning we don't need a hidden header element.
- Adds attr_list as an extension (I think it should always have been there?)
- Adds styling to make the (now visible) header elements match what was there before.
- Fixes sections not expanding when jumped to via permalink or searching

help/en/docs/css/grist.css

@@ -316,16 +316,16 @@ body {
 }
 
 /*
- * We want headers for the sake of searching, but don't want to see the huge padding and
- * surrounding empty paragraphs.
+ * Hide the empty paragraphs that are generated around headers in the expanding sections.
  */
-.wm-page-content summary h4,
-.wm-page-content summary p {
+.wm-page-content summary p:empty {
   display: none;
 }
-/* The <code> block that serves as a function header annoyingly gets auto-wrapped in a <p> */
-.wm-page-content summary p:not(:first-child) {
-  display: inline-block;
+
+/*
+ * Clean up any extra space used by paragraphs in the header.
+ */
+.wm-page-content summary p {
   margin: 0;
 }