Improve blog post display

* Add a post date to each post
* Do not show the post date for tours
* Only show posts tagged "current-event" on the home page (hiding 37c3 entries)
* Use a custom template for sorting the summary list by title (instead of the default by date)

content/en/posts/2024-10-01-coming-up.md

@@ -1,6 +1,9 @@
 ---
 title: 'Get excited about the tours at 38c3!'
 date: 2024-10-31T09:00:00+01:00
+tags:
+  - current-event
+  - 38c3
 ---
 
 We are preparing tours again for 38c3. As soon as we have nailed down the details, we'll let you know here.

content/en/posts/2024-11-18-shop-open.md

@@ -1,6 +1,9 @@
 ---
 title: 'The shop is open for 38c3!'
 date: 2024-11-18T09:00:00+01:00
+tags:
+  - current-event
+  - 38c3
 ---
 
 (Almost) all tours are on this [website](../38c3/), and [the shop](https://tickets.hamburg.ccc.de/hackertours/38c3/) is open for you to book a spot on one of the tours! Over the coming weeks, we will highlight the tours on Mastodon [@hackertours@chaos.social](https://chaos.social/@hackertours), so be sure to follow us there.

content/en/posts/_index.md

@@ -1,5 +1,6 @@
 ---
 title: News
+type: posts
 weight: 2
 menus:
   main: