[Feature] Add option to auto-install laravel-ide-helper

[othyn]

I find whenever I create new repo, I always add this, so add a flag to install and configure the plugin during usage of the installation script.

Prerequisites:

• Need to find out a clean way to add lines under other lines, as sed had trouble with this.

Todo:

• Run docker-compose run --rm composer require --dev barryvdh/laravel-ide-helper
• Run php artisan ide-helper:generate
• Run php artisan ide-helper:meta
• Within docker/app/entrypoint.sh add the following line under php artisan migrate:fresh --seed on line 23, so line 24 reads:
  php artisan ide-helper:models --nowrite # Has to be run with access to DB
• In composer.json add:

            "@php artisan ide-helper:generate",
            "@php artisan ide-helper:meta"

Add this into the scripts, in both the post-autoload-dump and post-root-package-install stages.

• Add README entry for how to use this.
• Update install script README help reference.