feat: Add left handed option for post button

Added a left handed toggle in the app configuration section to turn on
left handed mode which moves the post button to the left side. Nearly
done. May just need to fix an initialization bug.

Closes: #282
Changelog-Added: Left hand option for post button

damus/Views/PostButton.swift

@@ -34,14 +34,20 @@ func PostButton(action: @escaping () -> ()) -> some View {
     .keyboardShortcut("n", modifiers: [.command, .shift])
 }
 
-func PostButtonContainer(action: @escaping () -> ()) -> some View {
+func PostButtonContainer(userSettings: UserSettingsStore, action: @escaping () -> Void) -> some View {
+    let is_left_handed = userSettings.left_handed.self
     return VStack {
         Spacer()
 
         HStack {
-            Spacer()
-            PostButton(action: action)
+            if is_left_handed != true {
+                Spacer()
+                
+                PostButton(action: action)
+            } else {
+                PostButton(action: action)
+                Spacer()
+            }
         }
     }
 }
-