patch 8.1.0586: :digraph output is not easy to read
Problem: :digraph output is not easy to read.
Solution: Add highlighting for :digraphs. (Marcin Szamotulski, closes #3572)
Also add section headers for :digraphs!.
diff --git a/runtime/doc/digraph.txt b/runtime/doc/digraph.txt
index 14a5676..3b6424a 100644
--- a/runtime/doc/digraph.txt
+++ b/runtime/doc/digraph.txt
@@ -24,7 +24,9 @@
1. Defining digraphs *digraphs-define*
*:dig* *:digraphs*
-:dig[raphs] show currently defined digraphs.
+:dig[raphs][!] Show currently defined digraphs.
+ With [!] headers are used to make it a bit easier to
+ find a specific character.
*E104* *E39*
:dig[raphs] {char1}{char2} {number} ...
Add digraph {char1}{char2} to the list. {number} is