frontend: Add footer

index.html

@@ -40,6 +40,17 @@
       </form>
 
       <div id="hash-container"><span id="hash"></span></div>
+
+      <footer>
+        <p>
+          The hash is calculated in your browser
+          and never leaves your device.
+        </p>
+        <p>
+          This application is free software, released under the <a href="https://www.gnu.org/licenses/agpl-3.0.en.html"><code>AGPLv3</code></a>
+          (<a href="https://git.sbruder.de/simon/password-hash-self-service">Source code</a>).
+        </p>
+      </footer>
     </div>
 
     <script type="module" src="app.js"></script>

style.css

@@ -22,3 +22,9 @@ body {
   font-family: monospace;
   line-break: anywhere;
 }
+
+footer {
+  margin-top: 1em;
+  border-top: 1px solid black;
+  font-size: 14px;
+}