docs(playground): update UI hint wording to include Ctrl+Shift+Enter shortcut

Author: nishtha-agarwal-211

web-app/index.html

@@ -381,7 +381,7 @@ <h2 class="playground-title">🐍 Python Playground</h2>
             <a href="https://pyodide.org" rel="noopener noreferrer" target="_blank">Pyodide</a>. No install, no backend.
           </p>
           <p class="playground-hint">
-            <kbd>Ctrl</kbd>+<kbd>Enter</kbd> runs code &nbsp;·&nbsp;
+            <kbd>Ctrl</kbd>+<kbd>Enter</kbd> / <kbd>Ctrl</kbd>+<kbd>Shift</kbd>+<kbd>Enter</kbd> runs code &nbsp;·&nbsp;
             <kbd>Ctrl</kbd>+<kbd>Shift</kbd>+<kbd>L</kbd> clears console &nbsp;·&nbsp;
             <kbd>Tab</kbd> inserts 4 spaces
           </p>

web-app/js/playground.js

@@ -480,7 +480,7 @@
         ...CM.completionKeymap,
         /* Search */
         ...CM.searchKeymap,
-        /* Ctrl/Cmd + Enter → Run Code */
+        /* Ctrl/Cmd + Enter or Ctrl/Cmd + Shift + Enter → Run Code */
         {
           key: "Ctrl-Enter",
           mac: "Cmd-Enter",
@@ -489,6 +489,14 @@
             return true;
           },
         },
+        {
+          key: "Ctrl-Shift-Enter",
+          mac: "Cmd-Shift-Enter",
+          run: function () {
+            runCode();
+            return true;
+          },
+        },
         /* Ctrl/Cmd + Shift + L → Clear Console */
         {
           key: "Ctrl-Shift-l",