Added Buy Me A Coffee button

Added new Buy Me A Coffee button using the color palette and assets from the official  Buy Me A Coffee creator kit.

css/brands.css

@@ -94,6 +94,16 @@ button:hover,
   filter: brightness(90%);
 }
 
+/* Buy Me a Coffee */
+.button.button-coffee {
+  color: #100a26;
+  background-color: #ffdd00;
+}
+.button.button-coffee:hover,
+.button.button-coffee:focus {
+  filter: brightness(90%);
+}
+
 /* Cash App */
 .button.button-cashapp {
   color: #ffffff;

index.html

@@ -335,6 +335,11 @@
             src="images/icons/web.svg" alt="Web Logo">Website</a>
         <br>
 
+        <!-- Buy Me a Coffee -->
+        <a class="button button-coffee" href="#" target="_blank" rel="noopener"><img class="icon"
+            src="images/icons/coffee.svg" alt="Buy Me a Coffee">Buy Me a Coffee</a>
+        <br>
+
         <br>
         <p>Build your own by forking <a href="https://littlelink.io" target="_blank" rel="noopener">LittleLink</a>.</p>