Guide: move more screencasts to own field

Author: distantnative

content/docs/1_guide/15_cache/guide.txt

@@ -14,10 +14,14 @@ Icon: database
 
 ----
 
-Text:
+Screencast:
 
 (screencast: https://youtu.be/EVVORXaZThU title: Faster with caching text: Learn how Kirby can help you to keep even your more complex sites with lots of content performant.)
 
+----
+
+Text:
+
 ## Caching pages
 
 You can enable Kirby's page cache in your `config.php` file with the `cache.pages` option:

content/docs/1_guide/7_blueprints/2_fields/guide.txt

@@ -6,7 +6,7 @@ Intro: Fields are an essential part of the configuration and have very powerful
 
 ----
 
-Screencasts:
+Screencast:
 
 (screencast: https://www.youtube.com/watch?v=cOUmDlvsPaE title: Fun with fields text: Learn how to create intuitive blueprints for your editors, how to create field layouts, inline help and more.)