runtime(doc): add some docs for file-watcher programs

fixes: #15733

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 48ca25a..40dc139 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1151,12 +1151,13 @@
 	useful for example in source trees where all the files are symbolic or
 	hard links and any changes should stay in the local source tree, not
 	be propagated back to the original source.
-							*crontab*
+								*crontab*
 	One situation where "no" and "auto" will cause problems: A program
 	that opens a file, invokes Vim to edit that file, and then tests if
 	the open file was changed (through the file descriptor) will check the
 	backup file instead of the newly created file.  "crontab -e" is an
-	example.
+	example, as are several |file-watcher| daemons like inotify.  In that
+	case you probably want to switch this option.
 
 	When a copy is made, the original file is truncated and then filled
 	with the new text.  This means that protection bits, owner and