Add "static analysis" Composer keyword (#9)

As per https://getcomposer.org/doc/04-schema.md#keywords by including "static analysis" as a keyword in the `composer.json` file, Composer 2.4.0-RC1 and later will prompt users if the package is installed with `composer require` instead of `composer require --dev`. See composer/composer#10960 for more info.

Author: GaryJones

composer.json

@@ -6,6 +6,7 @@
       "phpcs",
       "coding",
       "standard",
+      "static analysis",
       "moderntribe",
       "code",
       "style",