runtime(doc): Fix typos in several documents

closes: #15034

Signed-off-by: h-east <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/terminal.txt b/runtime/doc/terminal.txt
index 2641611..e918394 100644
--- a/runtime/doc/terminal.txt
+++ b/runtime/doc/terminal.txt
@@ -648,7 +648,7 @@
 		Get the Job associated with terminal window {buf}.
 		{buf} is used as with |term_getsize()|.
 		Returns |v:null| when there is no job. In Vim9 script, return
-		null_job when there is no job.
+		|null_job| when there is no job.
 
 		Can also be used as a |method|: >
 			GetBufnr()->term_getjob()