all: link the markdown sources into the main README.md

Signed-off-by: Paul Moore <[email protected]>

Author: pcmoore

README.md

@@ -2,7 +2,6 @@
 
 ![](./src/images/logo.png)
 
-
 ## Introduction
 
 This Notebook should help with explaining:
@@ -49,6 +48,13 @@ Android.
 **Object Classes and Permissions** - Describes the SELinux object
 classes and permissions.
 
+## Viewing the Notebook Directly on GitHub
+
+The SELinux Notebook can be viewed directly on GitHub, one section at a time,
+starting with the table of contents at the link below:
+
+* [The SELinux Notebook](src/toc.md)
+
 ## Copyright Information
 
 Copyright © 2020 [*Richard Haines*](mailto:[email protected]).