Issue #3409362 by quietone, smustgrave: Fix spelling of some words with 'un' prefix

(cherry picked from commit de952edf2d0f570d1117a92c025940fe56a62983)

Author: longwave

Git.php

@@ -2,6 +2,8 @@
 
 namespace Drupal\Composer\Plugin\Scaffold;
 
+// cspell:ignore unmatch
+
 use Composer\IO\IOInterface;
 use Composer\Util\ProcessExecutor;
 

README.md

@@ -19,7 +19,7 @@ possible; for example, a project layout very similar to the current
 [drupal-composer/drupal-project](https://github.com/drupal-composer/drupal-scaffold)
 template will also be provided. When one of these projects is used, the user
 should be able to use `composer require` and `composer update` on a Drupal site
-immediately after untarring the downloaded archive.
+immediately after extracting the downloaded archive.
 
 Note that the dependencies of a Drupal site are only able to scaffold files if
 explicitly granted that right in the top-level composer.json file. See