Improve README and Example class

[NewtonMan]

Description

Improvement on Example class and README with more instructions to Maven users

Details

There are some errors in the Example class and was not totally clear that we need to install this before add dependency to project POM

Testing

Just executing the Example class

Checklist

Overview

• I have filled out all REQUIRED sections above
• PR does one thing
  • If it is hard to explain how any codes changes are related to each other then it most likely needs to be more than one PR
• Any Public API changes are explained in the PR details and conform to existing APIs

Testing

• I have personally tested this on my device, or explained why that is not possible

Final pass

• Code is as readable as possible.
  • Simplify with less code, followed by splitting up code into well named functions and variables, followed by adding comments to the code.
• I have reviewed this PR myself, ensuring it meets each checklist item
  • WIP (Work In Progress) is ok, but explain what is still in progress and what you would like feedback on. Start the PR title with "WIP" to indicate this.

[NewtonMan]

Please, anyone can review this?
@gdeglin @leemunroe @jmadler @jkasten2