Fix formatting in admonitions documentation (#3129)

Author: reakaleek

docs/syntax/admonitions.md

@@ -24,6 +24,7 @@ A relevant piece of information with no serious repercussions if ignored.
 
 :::{note}
 This is a note.
+
 It can span multiple lines and supports inline formatting.
 :::
 
@@ -34,6 +35,7 @@ It can span multiple lines and supports inline formatting.
 ```markdown
 :::{note}
 This is a note.
+
 It can span multiple lines and supports inline formatting.
 :::
 ```
@@ -153,4 +155,4 @@ It can *span* multiple lines and supports inline formatting.
 ## Applies to information
 
 :::{include} _snippets/applies-to-admonitions.md
-:::
+:::