composer/plugin/drupal-8-scaffold#16 Add readme

README.md

+# Usage
+
+## Preparation
+
+- [Install composer](https://getcomposer.org): `sudo wget https://getcomposer.org/composer.phar --output-document=/usr/local/bin/composer && sudo chmod +x /usr/local/bin/composer`
+- Disable XDebug for CLI - optional: `sudo phpdismod -s cli xdebug`
+- [Install Prestissimo](https://github.com/hirak/prestissimo) - optional: `sudo composer global require "hirak/prestissimo:^0.3"`
+
+## Create new project for local development
+
+```bash
+composer create-project lakedrops/d9-project [DIRNAME] --no-interaction
+cd [DIRNAME]
+```
+
+This will build the full structure and create a git repository which you can then use during the full live-cycle of that project.
+
+To install a new site with the included default configuration, use `drush site-install --existing-config` and you get a jump-start from that.
+
+## Deploy project to upstream stages
+
+For deployment, both initially and for later updates, follow this:
+
+```
+mkdir /PATH/TO/ROOT
+cd /PATH/TO/ROOT
+git clone YOUR-GIT-REPOSITORY .
+composer install
+```
+
+## Adding new and updating existing components
+
+Edit the composer.json file accoring to your requirements and then run `composer update`.
+
+## Adding JS packages
+
+### CKEditor Codesnippet
+
+```bash
+composer config repositories.codesnippet '{"type": "package","package": {"name": "ckeditorplugin/codesnippet","type": "drupal-library","version": "master","dist": {"type": "zip","url": "https://download.ckeditor.com/codesnippet/releases/codesnippet_4.7.3.zip","reference": "master"}}}'
+composer require ckeditorplugin/codesnippet:master drupal/codesnippet
+```
+
+### Chosen
+
+```bash
+composer config repositories.codesnippet '{"type": "package","package": {"name": "harvesthq/chosen","version": "1.8.2","type": "drupal-library","dist": {"url": "https://github.com/harvesthq/chosen/releases/download/v1.8.2/chosen_v1.8.2.zip","type": "zip"}}}'
+composer require harvesthq/chosen
+```
+
+# Links
+
+[Using Composer to install Drupal packages through Drupal.org](https://www.drupal.org/node/2718229)