fix: Add missing opening quote (#18534)

And thank you for this tool!

Author: Hywan

src/compiler/diagnosticMessages.json

@@ -2686,7 +2686,7 @@
         "category": "Message",
         "code": 6015
     },
-    "Specify module code generation: 'none', commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'.": {
+    "Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'.": {
         "category": "Message",
         "code": 6016
     },