Terraform tracks the state of your (remote) infrastructure. Meanwhile, git tracks your current files, including a couple build files (e.g. docs/architecture.dot.png).
For convenience, I've put in some git hooks to update the build every time you commit. However, you would need to trigger terraform apply after rebuilding those files (to deploy them to S3).
You may want to deploy changes to terraform (to a dev or feature environment) before committing to git. In that case, just run source hooks/pre-commit to build the files locally, first.