Reapply "Format talk page front matter"

This reverts commit 52659b653e.

source/_talks/goodbye-drush-make-hello-composer.md

@@ -2,25 +2,23 @@
 title: Goodbye Drush Make. Hello Composer!
 description: How to use Composer to manage your Drupal applications.
 speakerdeck:
-    id: 1c1e0e129ab34816bd4c4edb5f6642c2
-    ratio: "1.37081659973226"
-    url: https://speakerdeck.com/opdavies/goodbye-drush-make-hello-composer
+  id: 1c1e0e129ab34816bd4c4edb5f6642c2
+  ratio: "1.37081659973226"
+  url: https://speakerdeck.com/opdavies/goodbye-drush-make-hello-composer
 video:
-    type: youtube
-    id: ZL2FtRTX9Y8
+  type: youtube
+  id: ZL2FtRTX9Y8
 events:
-    -
-        name: PHP UK Conference 2018
-        location: London, UK
-        date: 2018-02-16
-        time: "14:40 - 15:40"
-        url: https://www.phpconference.co.uk
-        joindin: https://joind.in/talk/650ab
-    -
-        name: Drupal Bristol
-        location: Bristol, UK
-        url: https://www.drupalbristol.org.uk
-        date: 2016-11-17
+  - name: PHP UK Conference 2018
+    location: London, UK
+    date: 2018-02-16
+    time: "14:40 - 15:40"
+    url: https://www.phpconference.co.uk
+    joindin: https://joind.in/talk/650ab
+  - name: Drupal Bristol
+    location: Bristol, UK
+    url: https://www.drupalbristol.org.uk
+    date: 2016-11-17
 ---
 
 One of the main outcomes of Drupal 8 was “getting off the island” with third-party code included in core and adopting modern best practices from the wider PHP ecosystem - including [Composer][1], PHP’s dependency manager.