Added BlockHeading component

• Added:
- BlockHeading component

app/javascript/gabsocial/components/block_heading.js

@@ -0,0 +1,21 @@
+import Heading from './heading'
+
+export default class BlockHeading extends PureComponent {
+
+  static propTypes = {
+    title: PropTypes.string.isRequired,
+  }
+
+  render() {
+    const { title } = this.props
+
+    return (
+      <div className={[_s.default, _s.px15, _s.py10].join(' ')}>
+        <div className={[_s.default, _s.flexRow, _s.alignItemsCenter].join(' ')}>
+          <Heading size='h2'>{title}</Heading>
+        </div>
+      </div>
+    )
+  }
+
+}