Add regeneration info to version.h

src/objective-c/GRPCClient/private/version.h

@@ -31,7 +31,10 @@
  *
  */
 
-/* This file is autogenerated from template:
- * templates/src/objective-c/GRPCClient/private/version.h.template */
+/* This file is autogenerated from a template file. Please make
+ * modifications to
+ * `templates/src/objective-c/GRPCClient/private/version.h.template`
+ * instead. This file can be regenerated from the template by running
+ * `tools/buildgen/generate_projects.sh`. */
 
 #define GRPC_OBJC_VERSION_STRING @"1.1.0-dev"

templates/src/objective-c/GRPCClient/private/version.h.template

@@ -33,7 +33,10 @@
    *
    */
 
-  /* This file is autogenerated from template:
-   * templates/src/objective-c/GRPCClient/private/version.h.template */
+  /* This file is autogenerated from a template file. Please make
+   * modifications to
+   * `templates/src/objective-c/GRPCClient/private/version.h.template`
+   * instead. This file can be regenerated from the template by running
+   * `tools/buildgen/generate_projects.sh`. */
 
   #define GRPC_OBJC_VERSION_STRING @"${settings.version}"