Add additional sections to README

Author: mixja

README.md

@@ -8,4 +8,18 @@ To build this image:
 
 ```
 $ docker build -t <org-name>/microtrader-base .
-```
+```
+
+## Repository Timeline
+
+The following provides links to commits in this repository that represent important milestones in the course material:
+
+- Customizing ECS Container Instances - this commit represents the state of the repository once you have completed the Customizing ECS Container Instances module.
+
+## Errata
+
+No known issues.
+
+## Further Reading
+
+- [confd Quick Start Guide](https://github.com/kelseyhightower/confd/blob/master/docs/quick-start-guide.md)