vim-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 vim/vim#3572)
            Also add section headers for :digraphs!.
eae8ae1b2b

src/nvim/ex_docmd.c

@@ -10010,10 +10010,11 @@ static void ex_setfiletype(exarg_T *eap)
 
 static void ex_digraphs(exarg_T *eap)
 {
-  if (*eap->arg != NUL)
+  if (*eap->arg != NUL) {
     putdigraph(eap->arg);
-  else
-    listdigraphs();
+  } else {
+    listdigraphs(eap->forceit);
+  }
 }
 
 static void ex_set(exarg_T *eap)