New branch for continued Course Catalog API work

docs/en_us/platform_api/source/course_catalog/index.rst

+.. _edX Platform Course Catalog API:
+
+#####################################
+Course Catalog API Version 1.0
+#####################################
+
+.. toctree::
+    :maxdepth: 2
+
+    overview
+    catalog

docs/en_us/platform_api/source/course_catalog/overview.rst

+.. _Course Catalog API Overview:
+
+#############################
+Course Catalog API Overview
+#############################
+
+Use the Course Catalog API to obtain information about the catalogs that edX
+offers, as well as information about the courses in a specific catalog.
+
+.. contents::
+   :local:
+   :depth: 1
+
+*****************************************
+Course Catalog API Version and Status
+*****************************************
+
+The Course Catalog API is currently at version 1.0.
+
+*****************************
+Course Catalog API Endpoints
+*****************************
+
+The Course Catalog API includes the **Catalogs** resource. This resource
+supports the following tasks, methods, and endpoints.
+
+.. list-table::
+   :widths: 20 10 70
+   :header-rows: 1
+
+   * - Task
+     - Method
+     - Endpoint
+   * - :ref:`Get a list of all available course catalogs <Get a List of All
+     Course Catalogs>`
+     - GET
+     - /api/v1/catalogs/
+   * - :ref:`Get information about a specific catalog <Get Information About a
+     Specific Catalog>`
+     - GET
+     - /api/v1/catalogs/{id}/
+   * - :ref:`Get a list of all courses in a catalog <Get a List of All Courses
+     in a Catalog>`
+     - GET
+     - /api/v1/catalogs/{id}/courses/