Typo fix

src/main/java/com/maddyhome/idea/vim/group/NotificationService.kt

@@ -103,7 +103,7 @@ class NotificationService(private val project: Project?) {
   }
 
   fun enableRepeatingMode() = Messages.showYesNoDialog(
-    "Do you want to enable repeating keys in Mac OS X on press and hold?\n\n" +
+    "Do you want to enable repeating keys in macOS on press and hold?\n\n" +
       "(You can do it manually by running 'defaults write -g " +
       "ApplePressAndHoldEnabled 0' in the console).",
     IDEAVIM_NOTIFICATION_TITLE,

src/main/java/com/maddyhome/idea/vim/group/visual/VimVisualTimer.kt

@@ -35,7 +35,7 @@ import javax.swing.Timer
  *   If IdeaVim had reacted to this selection immediately, its listeners were called twice: after selection set and
  *   after selection removing. After there both operations vim would get normal mode, what is inconvenient because user
  *   expects vim to stay in insert mode.
- *   Same approach is used in some accented characters on MacOs and for Romaji layout in Japanese language (VIM-1725).
+ *   Same approach is used in some accented characters on macOS and for Romaji layout in Japanese language (VIM-1725).
  *
  * Because of this IdeaVim doesn't react to selection change immediately. After selection was changed, vim waits some
  *   time (100 ms by default) and enables visual mode (or any another) if selection was not changed during this time.

src/main/java/com/maddyhome/idea/vim/option/OptionsManager.kt

@@ -600,7 +600,7 @@ object LookupKeysData {
     "<Tab>", "<Down>", "<Up>", "<Enter>", "<Left>", "<Right>",
     "<C-Down>", "<C-Up>",
     "<PageUp>", "<PageDown>",
-    // New line in vim, but QuickDoc on MacOs
+    // New line in vim, but QuickDoc on macOS
     "<C-J>",
     // QuickDoc for non-mac layouts.
     // Vim: Insert next non-digit literally (same as <Ctrl-V>). Not yet supported (19.01.2020)