add/clarify comments in prefix loader files

Author: lobsterkatie

packages/nextjs/src/config/loaders/prefixLoader.ts

@@ -22,6 +22,7 @@ function prefixLoader(this: LoaderThis, userCode: string): string {
   const { distDir } = this.getOptions ? this.getOptions() : this.query!;
 
   const templatePath = path.resolve(__dirname, '../templates/prefixLoaderTemplate.js');
+  // make sure the template is included when runing `webpack watch`
   this.addDependency(templatePath);
 
   // Fill in the placeholder

packages/nextjs/src/config/templates/prefixLoaderTemplate.ts

@@ -1,5 +1,6 @@
 // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access, @typescript-eslint/no-explicit-any
 (global as any).__rewriteFramesDistDir__ = '__DIST_DIR__';
 
-// We need this to make this file an ESM module, which TS requires when using `isolatedModules`.
+// We need this to make this file an ESM module, which TS requires when using `isolatedModules`, but it doesn't affect
+// the end result - Rollup recognizes that it's a no-op and doesn't include it when building our code.
 export {};