Add overview and best practice

Author: bryantson

README.md

@@ -1,6 +1,14 @@
 # Custom GitHub Copilot workshop with Python Django, ReactJS, and PostgreSQL stacks
 
-Welcome to a custom Copilot workshop prepared by GitHub’s Expert Service team! In this workshop, you will get to deliver a custom Copilot workshop that can help to build a full stack web application that involves a front end layer using ReactJS, a backend layer using Python Django, and a database layer using PostgreSQL. Because 
+![GitHub Copilot Workshop](./images/cover-copilot.jpg)
+
+Welcome to a custom Copilot workshop prepared by **GitHub’s Expert Service team**! 
+
+In this workshop, you will get to deliver a custom Copilot workshop that can help to build a full stack web application that involves a front end layer using ReactJS, a backend layer using Python Django, and a database layer using PostgreSQL.
+
+Because this workshop involves several technology stacks, it is essential that you need to meet prerequisites as outlined from [Before getting started](docs/2_BeforeGettingStarted/README.md) if you want to follow along. Otherwise, you can always listen to what GitHub Expert Service team's instructor demo to see how it works in practice.
+
+Without further ado, let's get started.
 
 ## Table of Contents
 

docs/6_BuildReactJS/README.md

@@ -102,7 +102,7 @@ Then, when you save to reload your ReactJS web page, your updated ReactJS page m
 We can further parse those data to make them look prettier, but, for now, let’s focus on whether we can put those data into a nice table instead of a simple list. Select those HTML tags that print the data, and let’s ask this question in our GitHub Copilot Chat.
 
 ```bash
-How can I put those highlighted codes into a nice bootstrap table instead??
+How can I put those highlighted codes into a nice bootstrap table instead?
 ```
 
 ![Print Table](./images/15_PrintTable.jpg)

docs/7_LessonsLearned/README.md

@@ -1,3 +1,22 @@
 # Best practices and lessons learned from GitHub Copilot Workshop
 
-Throughout this workshop, you have learned
+Congratulation on finishing this GitHub Copilot worshop! Hopefully, this workshop session was useful to understand how GitHub Copilot works in practice when you work with a full stack project.
+
+## What you have learned
+
+Here is a summary of what you have learned.
+
+- You used GitHub Copilot Chat in conjunction with GitHub Copilot's file functionalities to intelligently build a full end-to-end Python Django, PostgreSQL, and ReactJS stacks application.
+- You know when to take GitHub Copilot's suggestions and how to use prompt engineering to get right answers first time.
+
+## Best practices with GitHub Copilot
+
+Although GitHub Copilot keeps getting improved, here some general suggestions when you with GitHub Copilot, and many of these practices involve art of mastering **prompt engineering.**
+
+- When you ask GitHub Copilot within file as comments or function names, try to be detailed as much as possible if you want GitHub Copilot to get it right first time. You can always override the suggestions given by GitHub Copilot.
+- When you ask GitHub Copilot Chat, start with something simple and have a conversation with GitHub Copilot to provide more contexts as you keep checking if suggestions are correct. For example, don't start with something like `Can you help me to create a ReactJS application that works with my Python Django application and retrieves data in a table format?` Most likely, you will get some irrelevant result from GitHub Copilot Chat. Instead, try to start with `Can you help me to create a ReactJS application` and give more contexts to build your work toward building projects that you have in mind.
+- Don't always 100% trust what GitHub Copilot make a suggestion to you, and always use your judgement to see what is right or wrong. Again, you are the main developer while your GitHub Copilot is just your assistance pilot.
+
+I can add more stuffs, but this is just your start of journey. Congratulation on finishing your GitHub Copilot workshop course!
+
+![Congratulation](./images/congrat.jpg)