startup: -es/-Es (silent/batch mode): skip swapfile #8540

To use Nvim as a scripting engine the side-effects of swapfiles and user
config should be avoided by default.

runtime/doc/starting.txt

@@ -208,6 +208,7 @@ argument.
 			echo foo | nvim -V1 -es
 <
 		User |init.vim| is skipped (unless given with |-u|).
+		Swap file is skipped (like |-n|).
 		|$TERM| is not used.
 
 		If stdin is not a TTY:
@@ -255,7 +256,7 @@ argument.
 		{not available when compiled without the |+eval| feature}
 
 							*-n*
--n		No swap file will be used.  Recovery after a crash will be
+-n		No |swap-file| will be used.  Recovery after a crash will be
 		impossible.  Handy if you want to view or edit a file on a
 		very slow medium (e.g., a floppy).
 		Can also be done with ":set updatecount=0".  You can switch it

runtime/doc/vim_diff.txt

@@ -346,7 +346,10 @@ Shell:
 
 Startup:
   |-e| and |-es| invoke the same "improved Ex mode" as -E and -Es.
-  |-E| and |-Es| reads stdin as text (into buffer 1).
+  |-E| and |-Es| read stdin as text (into buffer 1).
+  |-es| and |-Es| have improved behavior:
+    - Quits automatically, don't need "-c qa!".
+    - Skips swap-file dialog.
   |-s| reads Normal commands from stdin if the script name is "-".
   Reading text (instead of commands) from stdin |--|:
     - works by default: "-" file is optional