Homepage: credit packs in the membership section

index.html

@@ -464,6 +464,10 @@
           <h3>Everyone gets the same allowance</h3>
           <p>Today, every member gets a $15 monthly credit for chat and API alike, whether you pay $10 or $20.</p>
         </div>
+        <div class="mcard">
+          <h3>Need more? Add credits</h3>
+          <p>When the allowance isn't enough, buy a credit pack. Credits never expire, carry over month to month, and kick in only after your allowance is used.</p>
+        </div>
         <div class="mcard">
           <h3>Chat, API, and a vote</h3>
           <p>One membership opens the chat, the developer API, and a seat in governance.</p>