ENH: HTML: Collapse orig source docstring into <details><summary>

Fixes #192

Author: kernc

pdoc/templates/css.mako

@@ -219,7 +219,7 @@
       background: inherit;  /* Don't grey-back parameters */
     }
 
-    .source summary,
+    .source > summary,
     .git-link-div {
       color: #666;
       text-align: right;
@@ -243,6 +243,7 @@
     .source pre code {
       font-size: 12px;
       overflow: visible;
+      min-width: max-content;
     }
   .hlist {
     list-style: none;

pdoc/templates/html.mako

@@ -424,6 +424,17 @@
     <script>window.addEventListener('DOMContentLoaded', () => {
         hljs.configure({languages: ['bash', 'css', 'diff', 'graphql', 'ini', 'javascript', 'json', 'plaintext', 'python', 'python-repl', 'rust', 'shell', 'sql', 'typescript', 'xml', 'yaml']});
         hljs.highlightAll();
+        /* Collapse source docstrings */
+        setTimeout(() => {
+            [...document.querySelectorAll('.hljs.language-python > .hljs-string')]
+                .filter(el => el.innerHTML.length > 200 && ['"""', "'''"].includes(el.innerHTML.substring(0, 3)))
+                .forEach(el => {
+                    let d = document.createElement('details');
+                    d.classList.add('hljs-string');
+                    d.innerHTML = '<summary>"""</summary>' + el.innerHTML.substring(3);
+                    el.replaceWith(d);
+                });
+        }, 100);
     })</script>
   % endif