[README] Add "XPC service" to "Templates included" section

Adjust grammar in description section

Both changes thanks to @L1ghtmann

README.md

@@ -4,7 +4,7 @@ A set of [NIC](<https://theos.dev/docs/nic>) templates available to be installed
 
 [theos/templates](<https://github.com/theos/templates>) provides a set of templates which are installed with Theos by default.
 
-This module provides additional templates for project which target legacy operating systems and configurations.
+This module provides additional templates for projects which target legacy operating systems and configurations.
 
 ## Templates included
 
@@ -13,6 +13,7 @@ This module provides additional templates for project which target legacy operat
 - Cydget
 - Flipswitch switch
 - Notification Center widget (iOS 5/6 and iOS 7+)
+- XPC service
 
 ### Installation