chore Polish deprecation message

src/configure.ts

@@ -1,7 +1,7 @@
 import path from 'path';
 import fs from 'fs';
 import { exec } from 'child_process';
-
+import chalk from 'chalk';
 import { CACHE_FOLDER, SASS_LOAD_PATHS_CONFIG } from './constants';
 import { createCacheFolderIfNeeded } from './utils';
 import { debug } from './preview';
@@ -53,16 +53,14 @@ export async function jestPreviewConfigure(
   }
 
   externalCss?.forEach((cssFile) => {
-    // TODO: To add a yellow warning here
-    // `chalk` is installed in https://github.com/nvh95/jest-preview/pull/129, so we can merge that PR first
-    // Link to migration guide (haven't written yet)
-    // https://github.com/nvh95/jest-preview/issues/124
     // Avoid name collision
     // Example: src/common/styles.css => cache-src___common___styles.css
     console.log(
-      'externalCss is deprecated. Please import css files directly in your setup file.',
+      chalk.yellow(
+        'externalCss is deprecated. Please import css files directly in your setup file.',
+        'See the migration guide at www.jest-preview.com/blog/deprecate-externalCss',
+      ),
     );
-    console.log('See the instruction to migrate here: TODO');
     const delimiter = '___';
     const destinationBasename = `cache-${cssFile.replace(/\//g, delimiter)}`;
     const destinationFile = path.join(CACHE_FOLDER, destinationBasename);