Add shorter, more compact docs for AWS CLI, Docker, AWS SAM CLI setup than what's already out there

[ghost]

Is your feature request related to a problem? Please describe.

Today, before users can use the AWS Toolkit to do AWS serverless development or to run/debug AWS Lambda functions locally, users are currently sent off to the AWS CLI and AWS SAM CLI setup documentation that's spread out over the AWS website--as well as sent off to the Docker setup documentation elsewhere--to set up these prerequisites manually.

Describe the solution you'd like

Add documentation to the AWS Toolkit for VS Code User Guide that contains summarized, compact sets of commands that customers can run to manually install the AWS CLI, Docker, and the AWS SAM CLI as quick as possible.

Describe alternatives you've considered

Ideally, there should be a way to do this a lot faster than a bunch of manual commands. But for now, hopefully this would be a better documentation experience than what it is currently.

[justinmk3]

Could make sense to put this in the Setup section of the quickstart page: https://github.com/aws/aws-toolkit-vscode/blob/3a8914b575bb54138095f0ca9851d38bec5f8b4d/extension-readme.md#setup