Fix grammar in tip (#838)

Author: wl2776

src/Resources/Locales/en_US.axaml

@@ -355,8 +355,8 @@
   <x:String x:Key="Text.Histories.Header.SHA" xml:space="preserve">SHA</x:String>
   <x:String x:Key="Text.Histories.Header.Time" xml:space="preserve">COMMIT TIME</x:String>
   <x:String x:Key="Text.Histories.Selected" xml:space="preserve">SELECTED {0} COMMITS</x:String>
-  <x:String x:Key="Text.Histories.Tips" xml:space="preserve">Holding 'Ctrl' or 'Shift' to select multiple commits.</x:String>
-  <x:String x:Key="Text.Histories.Tips.MacOS" xml:space="preserve">Holding ⌘ or ⇧ to select multiple commits.</x:String>
+  <x:String x:Key="Text.Histories.Tips" xml:space="preserve">Hold 'Ctrl' or 'Shift' to select multiple commits.</x:String>
+  <x:String x:Key="Text.Histories.Tips.MacOS" xml:space="preserve">Hold ⌘ or ⇧ to select multiple commits.</x:String>
   <x:String x:Key="Text.Histories.Tips.Prefix" xml:space="preserve">TIPS:</x:String>
   <x:String x:Key="Text.Hotkeys" xml:space="preserve">Keyboard Shortcuts Reference</x:String>
   <x:String x:Key="Text.Hotkeys.Global" xml:space="preserve">GLOBAL</x:String>