Docs - Blueprints - Resources: Highlight installPlugin and installThe…

…me steps and most common resouces for them (#1733)

Highlight installPlugin and installTheme steps and most common resouces
for them. Also highlight [GitHub Proxy](playground.wordpress.net/proxy)
tool.

## Motivation for the change, related issues
Because installation of plugins and themes from both official WP
directories and zips from repos are one of the most recurrent actions to
do in blueprints.

packages/docs/site/docs/blueprints/04-resources.md

@@ -6,7 +6,11 @@ slug: /blueprints/steps/resources
 
 Resource References allow you use external files in Blueprints
 
-In the `installPlugin` step in the example above, we reference the `https://downloads.wordpress.org/plugins/friends.latest-stable.zip` file by using the `wordpress.org/plugins` resource reference.
+:::info
+Blueprints steps such as [[`installPlugin`](/blueprints/steps#InstallPluginStep)] or [`installTheme`](/blueprints/steps#InstallThemeStep) require a location of the plugin or theme to be installed.
+
+That location can be defined as [a `URL` resource](#urlreference) of the `.zip` file containg the theme or plugin. It can also be defined as a [`wordpress.org/plugins`](#corepluginreference) or [`wordpress.org/themes`](#corethemereference) resource for thouse plugins/themes published in the official WordPress directories.
+:::
 
 The following resource references are available:
 
@@ -37,7 +41,11 @@ To use the URLReference resource, you need to provide the URL of the file. For e
 The resource `url` type works really in combination with blueprint steps such as [`installPlugin`](/blueprints/steps#InstallPluginStep) or
 [`installTheme`](http://localhost:3000/wordpress-playground/blueprints/steps#InstallThemeStep). These steps require a `ResourceType` to define the location of the plugin or the theme to install.
 
-With a `"resource": "url"` we can define the location of a `.zip` containing the plugin/theme via a URL that can point direclty to a GitHub repo. To avoid CORS issues, the Playground project provides a [GitHub proxy](https://playground.wordpress.net/proxy) that also allows you to generate a `.zip` from a repository (or even a folder inside a repo) containing your plugin or theme.
+With a `"resource": "url"` we can define the location of a `.zip` containing the plugin/theme via a URL that can point direclty to a GitHub repo.
+
+:::tip
+The Playground project provides a [GitHub Proxy](https://playground.wordpress.net/proxy) that allows you to generate a `.zip` from a repository (or even a folder inside a repo) containing your plugin or theme. This tool is very useful for avoiding CORS issues, among others..
+:::
 
 ### CoreThemeReference