Address CI lint failures by adding shortcode

Shortcode is apparently necessary because raw HTML tags are not allowed
- and that fixes the line length violation too.

The double commenting in the shortcode of '<!-- {#' is necessary to
ensure that the comment is syntax-highlighted nicely and that Tera does
not try to interpret the example snippet as a macro invocation.

content/news/052/index.md

@@ -72,9 +72,9 @@ If needed, a section can be split into subsections with a "------" delimiter.
 ## Game Updates
 
 ### [Untitled Pixel Wizards Game][pixel-wizards]
-<video controls autoplay muted loop> <source type="video/mp4" src="untitled-pixel-wizards-game.mp4" onerror="parentNode.parentElement.innerText = 'Sorry, your browser does not support the video codec. Try a different browser!'"> />
-</video>
-_Enemies now perceive, pursue and attack.. and occasionally get burned to death._
+
+{{ embed_video(type="video/mp4", src="untitled-pixel-wizards-game.mp4",
+caption="Enemies now perceive, pursue and attack.. and occasionally get burned to death.") }}
 
 [![A Hound chases a player, and its corpse ragdolls after it is burned to death by a fireball](untitled-pixel-wizards-game.gif)][pixel-wizards]
 _Enemies now perceive, pursue and attack.. and occasionally get burned to death._

templates/shortcodes/embed_video.html

@@ -0,0 +1,11 @@
+<!-- {#
+Embed a video into a markdown file. Example usage:
+
+    {{ embed_video(type="video/mp4", src="my-video.mp4", caption="Some caption.") }}
+
+#} -->
+<video controls autoplay muted loop>
+    <source
+        type="{{ type }}" src="{{ src }}"
+        onerror="parentNode.parentElement.innerText = 'Sorry, this video does not exist or your browser does not support the video codec. Try a different browser!'" />
+</video> {% if caption %}<em>{{ caption }}</em>{% endif %}