minor #1575 A minor typo (amitmerchant1990)

This PR was merged into the 2.2.x-dev branch.

Discussion
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A minor typo

Hi,

I found a minor typo in this particular file. Kindly please check it and merge the pull request if you find it valid.

Thanks!

Commits
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8fd2b2bf Update organizing_controllers.rst

doc/organizing_controllers.rst

@@ -25,7 +25,7 @@ group them logically::
     $app->mount('/blog', $blog);
     $app->mount('/forum', $forum);
 
-    // define controllers for a admin
+    // define controllers for an admin
     $app->mount('/admin', function ($admin) {
         // recursively mount
         $admin->mount('/blog', function ($user) {