✨ Added "Button" card to the editor

refs https://github.com/TryGhost/Team/issues/1210

The button card lets you add a center or left-aligned button-styled link to your posts.

ghost/admin/app/services/feature.js

@@ -60,7 +60,6 @@ export default Service.extend({
     urlCache: feature('urlCache', {developer: true}),
     mediaAPI: feature('mediaAPI', {developer: true}),
     filesAPI: feature('filesAPI', {developer: true}),
-    buttonCard: feature('buttonCard', {developer: true}),
     calloutCard: feature('calloutCard', {developer: true}),
     nftCard: feature('nftCard', {developer: true}),
     accordionCard: feature('accordionCard', {developer: true}),

ghost/admin/app/templates/settings/labs.hbs

@@ -339,19 +339,6 @@
                         </div>
                     </div>
                 </div>
-                <div class="gh-expandable-block">
-                    <div class="gh-expandable-header">
-                        <div>
-                            <h4 class="gh-expandable-title">Cardmageddon - Button</h4>
-                            <p class="gh-expandable-description">
-                               Card for adding clicky things with urls
-                            </p>
-                        </div>
-                        <div class="for-switch">
-                           <GhFeatureFlag @flag="buttonCard" />
-                        </div>
-                    </div>
-                </div>
                 <div class="gh-expandable-block">
                     <div class="gh-expandable-header">
                         <div>

ghost/admin/lib/koenig-editor/addon/options/cards.js

@@ -167,8 +167,7 @@ export const CARD_MENU = [
             desc: 'Add a button to your post',
             matches: ['button'],
             type: 'card',
-            replaceArg: 'button',
-            isAvailable: 'feature.buttonCard'
+            replaceArg: 'button'
         },
         {
             label: 'Callout',