add footer with disclaimer about correctness

src/index.html

@@ -43,6 +43,10 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
             </form>
         </div>
 
+        <footer>
+            <p>Die richtigkeit der berechneten Note kann nicht garantiert werden</p>
+        </footer>
+
         <script src="rechner.js"></script>
     </body>
 </html>

src/stylesheet.css

@@ -34,6 +34,12 @@ html * {
   color: var(--text);
 }
 
+footer {
+    text-align: center;
+    width: 100%;
+    padding: 10px 0;
+}
+
 h1 {
   font-size: 24pt;
   font-weight: bolder;
@@ -77,6 +83,11 @@ input:focus {
   flex-direction: column;
 }
 
+#disclaimer {
+  position: absolute;
+  bottom: 0;
+}
+
 input[type=submit] {
   width: 82px;
   box-sizing: border-box;