runtime(doc): Add hint how to load termdebug from vimrc

fixes: #15256

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/terminal.txt b/runtime/doc/terminal.txt
index 6bc980b..b6204b2 100644
--- a/runtime/doc/terminal.txt
+++ b/runtime/doc/terminal.txt
@@ -1,4 +1,4 @@
-*terminal.txt*	For Vim version 9.1.  Last change: 2024 Jul 04
+*terminal.txt*	For Vim version 9.1.  Last change: 2024 Jul 14
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -1253,6 +1253,8 @@
 							*termdebug-starting*
 Load the plugin with this command: >
 	packadd termdebug
+<When loading the plugin from the |.vimrc| file, add the "!" attribute: >
+	packadd! termdebug
 <							*:Termdebug*
 To start debugging use `:Termdebug` or `:TermdebugCommand` followed by the
 command name, for example: >