Add file extension if not exists

Author: lkmadushan

src/cli.js

@@ -53,7 +53,11 @@ program.version(packageJson.version).usage('<command> [<args>]')
 program.command('init [filename]')
   .usage('[options] [filename]')
   .action(function (filename = 'tailwind.js') {
-    const destination = path.resolve(filename)
+    let destination = path.resolve(filename)
+    
+    if (! path.extname(filename).includes('.js')) {
+      destination += '.js'
+    }
 
     if (fs.existsSync(destination)) {
       console.log(`Destination ${destination} already exists, aborting.`)