To do

deploy
- Only show changing resources
- Ensure update count reflects everything that has changed
- Detect whether a deployment requires capabilities rather than automatically applying them
- Allow deploying over a stack that's REVIEW_IN_PROGRESS by killing the changset?
- After a failed deployment, show the logs
rm
- List stack contents and ask for confirmation
- Add --force flag
- Detect y as Y
ls
- Display in yaml(ish) format

Other ideas

Multiple deployments. Use a rain.yaml to specify multiple stacks in multiple regions/accounts.
doc - load documentation for a resource type
minify - try hard to get a template below the size limit
Do template parameter validation (especially multiple-template stacks - checking clashing outputs etc.)
- S3 buckets that exist or can't be created (e.g. recent deleted bucket with same name)
- Certificates that don't exist in the correct region (e.g. non us-east-1)
- Mismatching or existing "CNAMEs" for CloudFront distros
Blueprints (higher level constructs - maybe from CDK)
Store metadata in template?
- stack name
Magically add tags?
- Commit ID