Consistent ordering and formatting for talk events

Use a consistent format for talk events, with the most recent talk at
the top of the list with the rest in a descending order.

This removes the need to use a `reverse` filter in the events partial.

source/_talks/things-you-should-know-about-php.md

@@ -13,20 +13,21 @@ meta:
     image:
       url: '%site.assets_url%/assets/images/talks/things-you-should-know-about-php.png'
 events:
-  - name: Swansea Software Development Meetup (SSDC)
-    location: Swansea, UK
-    url: https://www.meetup.com/Swansea-Software-Development-Meetup
-    date: 2019-01-28
-
-  - name: PHP South West
-    location: Bristol, UK
-    url: https://www.meetup.com/php-sw/events/284341510
-    date: 2022-03-09
-
-  - name: PHP Stoke
+  -
+    name: PHP Stoke
     location: Stoke-on-Trent, UK
     url: https://www.eventbrite.com/e/php-stoke-tickets-429043128547
     date: 2023-01-12
+  -
+    name: PHP South West
+    location: Bristol, UK
+    url: https://www.meetup.com/php-sw/events/284341510
+    date: 2022-03-09
+  -
+    name: Swansea Software Development Meetup (SSDC)
+    location: Swansea, UK
+    url: https://www.meetup.com/Swansea-Software-Development-Meetup
+    date: 2019-01-28
 ---
 
 An introduction to PHP, presented to the Swansea Software Development Community (SSDC) meetup and PHP South West.