GitLab template for AWS SAM applications
### Problem to solve
AWS SAM model is becoming more and more popular. While we provide [examples](https://gitlab.com/gitlab-examples/aws-sam) on how to deploy to it, users currently have to start from scratch.
### Intended users
developers
### Further details
<!-- Include use cases, benefits, and/or goals (contributes to our vision?) -->
### Proposal
Provide project templates that match those provided by AWS.

### Permissions and Security
<!-- What permissions are required to perform the described actions? Are they consistent with the existing permissions as documented for users, groups, and projects as appropriate? Is the proposed behavior consistent between the UI, API, and other access methods (e.g. email replies)? -->
### Documentation
<!-- See the Feature Change Documentation Workflow https://docs.gitlab.com/ee/development/documentation/feature-change-workflow.html
Add all known Documentation Requirements here, per https://docs.gitlab.com/ee/development/documentation/feature-change-workflow.html#documentation-requirements -->
### Testing
<!-- What risks does this change pose? How might it affect the quality of the product? What additional test coverage or changes to tests will be needed? Will it require cross-browser testing? See the test engineering process for further guidelines: https://about.gitlab.com/handbook/engineering/quality/guidelines/test-engineering/ -->
### What does success look like, and how can we measure that?
<!-- Define both the success metrics and acceptance criteria. Note that success metrics indicate the desired business outcomes, while acceptance criteria indicate when the solution is working correctly. If there is no way to measure success, link to an issue that will implement a way to measure this. -->
### Links / references
Sample application for processing S3 events
Source code: https://github.com/aws-samples/cookiecutter-aws-sam-s3-rekognition-dynamodb-python
Docs: https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-example-s3.html
YouTube video that walks through the app: https://www.youtube.com/watch?v=DA0MtJkUVaY
GitLab Project templates
Project: https://gitlab.com/gitlab-org/project-templates
How to add new template: https://gitlab.com/gitlab-org/project-templates/contributing
issue