Configure the select all behavior by OS instead of application template

app/keymaps/base-darwin.json

@@ -8,5 +8,7 @@
   "window:reload": "mod+alt+l",
   "window:toggle-dev-tools": "meta+alt+i",
   "window:attach-to-xcode": "meta+alt+k",
-  "window:open-mailsync-logs": "meta+shift+k"
+  "window:open-mailsync-logs": "meta+shift+k",
+
+  "multiselect-list:select-all": "command+a"
 }

app/keymaps/base-linux.json

@@ -3,5 +3,7 @@
   "core:paste": "shift+insert",
   "window:toggle-full-screen": "f11",
   "window:reload": "mod+alt+l",
-  "window:toggle-dev-tools": "mod+alt+i"
+  "window:toggle-dev-tools": "mod+alt+i",
+  
+  "multiselect-list:select-all": "ctrl+a"
 }

app/keymaps/base-win32.json

@@ -1,5 +1,7 @@
 {
   "window:toggle-full-screen": "f11",
   "window:reload": "ctrl+shift+r",
-  "window:toggle-dev-tools": "ctrl+shift+i"
+  "window:toggle-dev-tools": "ctrl+shift+i",
+  
+  "multiselect-list:select-all": "ctrl+a"
 }

app/keymaps/templates/Apple Mail.json

@@ -10,8 +10,6 @@
   "navigation:go-to-tasks": "command+ctrl+7",
   "navigation:go-to-label": "command+ctrl+8",
 
-  "multiselect-list:select-all": "command+a",
-
   "core:find-in-thread": "mod+f",
   "core:find-in-thread-next": "mod+g",
   "core:find-in-thread-previous": "mod+shift+g",

app/keymaps/templates/Gmail.json

@@ -8,7 +8,6 @@
   "navigation:go-to-tasks": "g k",
   "navigation:go-to-label": "g l",
 
-  "multiselect-list:select-all": "* a",
   "multiselect-list:deselect-all": "* n",
 
   "thread-list:select-read": "* r",

app/keymaps/templates/Inbox by Gmail.json

@@ -2,7 +2,6 @@
   "application:new-message": ["c", "mod+n"],
 
   "navigation:go-to-inbox": "i",
-  "multiselect-list:select-all": "shift+x",
 
   "core:pop-sheet": "u",
   "core:previous-item": "k",

app/keymaps/templates/Outlook.json

@@ -26,7 +26,5 @@
   "contenteditable:outdent": "mod+shift+t",
   "contenteditable:indent": "mod+t",
 
-  "multiselect-list:select-all": "ctrl+a",
-
   "application:quit": "alt+f4"
 }