add footer with link to source

index.html

@@ -78,6 +78,10 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 			</div>
 		</div>
 
+		<footer>
+			<a href="https://scm.dairydemon.net/filifa/mcalc">source</a>
+		</footer>
+
 		<script type="module" src="main.js"></script>
   </body>
 </html>

styles.css

@@ -113,3 +113,10 @@ button {
 	grid-template-columns: subgrid;
 	gap: inherit;
 }
+
+footer {
+	display: flex;
+	justify-content: center;
+	font-size: small;
+	margin: 5%;
+}