default to not quitting when hitting esc at the top level.

I've been using this config option for years now so I don't think much of it,
but newcomers are going to find it annoying that hitting escape gets you out
of filtering/cherry-picking/patch-building mode, but also quits the app. So
if you want to exit all the modes you're in, you need to take care not to
press the key one too many times or the app will close.

We'll see if anybody gets mad about this change, but I think it's reasonable.
The only downside is that you won't be able to always quit by spamming the escape
key. If you're in a prompt panel, you'll need to hit escape to exit that, and
then 'q' at the top level. Or CTRL+C of course.

docs/Config.md

@@ -61,7 +61,7 @@ Default path for the config file:
   reporting: 'undetermined' # one of: 'on' | 'off' | 'undetermined'
   confirmOnQuit: false
   # determines whether hitting 'esc' will quit the application when there is nothing to cancel/close
-  quitOnTopLevelReturn: true
+  quitOnTopLevelReturn: false
   disableStartupPopups: false
   notARepository: 'prompt' # one of: 'prompt' | 'create' | 'skip'
   keybinding:

pkg/config/user_config.go

@@ -325,7 +325,7 @@ func GetDefaultConfig() *UserConfig {
 		Reporting:            "undetermined",
 		SplashUpdatesIndex:   0,
 		ConfirmOnQuit:        false,
-		QuitOnTopLevelReturn: true,
+		QuitOnTopLevelReturn: false,
 		Keybinding: KeybindingConfig{
 			Universal: KeybindingUniversalConfig{
 				Quit:                         "q",