[FEATURE] Document GitHub token permissions required

[bryantbiggs]

Is your feature request related to a problem? Please describe

• Document the GitHub permissions required for the personal access token for users
• Also, how can users use GitHub app auth instead of personal access tokens - https://docs.aws.amazon.com/codepipeline/latest/userguide/update-github-action-connections.html ?

[bryantbiggs]

Actually, we should update the codepipeline code to use the GitHub app auth route since its currently throwing a warning

│ Warning: The CodePipeline GitHub version 1 action provider is deprecated.
│ 
│   with module.codepipeline.aws_codepipeline.this,
│   on ../../modules/codepipeline/main.tf line 17, in resource "aws_codepipeline" "this":
│   17:       provider         = "GitHub"
│ 
│ Use a GitHub version 2 action (with a CodeStar Connection `aws_codestarconnections_connection`) instead. See https://docs.aws.amazon.com/codepipeline/latest/userguide/update-github-action-connections.html