Add asset-packagist repository and config. (#21)

Author: weitzman

README.md

@@ -114,3 +114,25 @@ section of composer.json:
     }
 }
 ```
+
+### How can I add js/css libraries using composer.json?
+
+It is possible to use frontend libraries with composer thanks to the
+asset-packagist repository (https://asset-packagist.org/).
+
+For example, to use colorbox:
+```
+composer require npm-asset/colorbox:"^0.4"
+
+```
+Composer will detect new versions of the library that meet your constraints.
+In the above example it will download anything from 0.4.* series of colorbox.
+
+When managing libraries with composer this way, you may not want to add it to
+version control. In that case, add specific directories to the .gitignore file.
+```
+# Specific libraries (which we manage with composer)
+web/libraries/colorbox
+```
+
+For more details, see https://asset-packagist.org/site/about

composer.json

@@ -17,6 +17,10 @@
         "commerce_base": {
             "type": "vcs",
             "url": "https://github.com/drupalcommerce/commerce_base"
+        },
+        "asset-packagist": {
+            "type": "composer",
+            "url": "https://asset-packagist.org"
         }
     },
     "config": {
@@ -36,6 +40,7 @@
         "drupal/swiftmailer": "~1.0",
         "drupal/token": "~1.0",
         "drupalcommerce/commerce_base": "dev-8.x-1.x",
+        "oomphinc/composer-installers-extender": "^1.1",
         "webflo/drupal-finder": "^1.0",
         "webmozart/path-util": "^2.3"
     },
@@ -74,12 +79,18 @@
         ]
     },
     "extra": {
+        "installer-types": [
+            "bower-asset",
+            "npm-asset"
+        ],
         "installer-paths": {
             "web/core": [
                 "type:drupal-core"
             ],
             "web/libraries/{$name}": [
-                "type:drupal-library"
+                "type:drupal-library",
+                "type:bower-asset",
+                "type:npm-asset"
             ],
             "web/modules/contrib/{$name}": [
                 "type:drupal-module"