Add custom links to app documentation

docs/introduction.rst

@@ -1,4 +1,18 @@
-Introduction
-============
+InvenTree
+=========
 
-This is a test
+InvenTree is an open source inventory management system which provides powerful low-level part management and stock tracking functionality.
+
+The core of the InvenTree software is a Python/Django database backend whi
+
+
+Django Apps
+===========
+
+The InvenTree Django ecosystem provides the following 'apps' for core functionality:
+
+* `InvenTree </api/InvenTree/index.html>`_ - High level management functions
+* `Build </api/build/index.html>`_ - Part build projects
+* `Company </api/company/index.html>`_ - Company management (suppliers / customers)
+* `Part </api/part/index.html>`_ - Part management
+* `Stock </api/stock/index.html>`_ - Stock management