Update AWSx EKS Guides

[desteves]

### Tasks
- [x] Update examples to use the new program shortcode
- [x] Include examples for missing languages (mostly JavaScript)
- [x] Update the makrdown to adhere to our style guide, added clarity, and links where relevant
- [x] Updated pre-reqs list

[desteves]

Addresses community reported issue tracked here

[desteves]

PR to update the AWSx EKS Guides.

[cnunciato]

Assigning myself here to review the state of this work and determine what's left to bring it over the line.