Add license footer to HTML output.

src/generators/html.cpp

@@ -92,7 +92,14 @@ void write_html(ostream &out, const vector<entry_type> &entries)
         out << "    </details>\n";
     }
 
-    out << "  </body>\n</html>\n";
+    out << R"(
+    <p class="footer" style="text-align: right;">
+      <a href="https://schlomp.space/FediBlock">Sourcecode</a> licensed under the
+      <a href="https://www.gnu.org/licenses/agpl-3.0.html">AGPL-3.0-only</a>.
+    </p>
+  </body>
+</html>
+)";
 }
 
 void copy_screenshots(const fs::path &directory)