feat: add specific operations

grammar.js

@@ -50,7 +50,19 @@ module.exports = grammar({
     ),
 
     prefix: _ => /[a-z0-9]+/,           // allow lowercase alphanumeric
-    operation: _ => /[A-Z]+/,           // must be all uppercase
     file_path: _ => /[^ \t\n][^\n]*/,   // must not start with space or newline
+    operation: $ => choice(
+      $.op_add,
+      $.op_delete,
+      $.op_move,
+      $.op_copy,
+      $.generic_operation
+    ),
+    
+    op_add: _ => choice("A", "ADD"),
+    op_delete: _ => choice("D", "DELETE"),
+    op_move: _ => choice("M", "MV", "MOVE", "RENAME"),
+    op_copy: _ => choice("C","COPY"),
+    generic_operation: _ => /[A-Z]+/,
   }
 });