* fix IAM in examples
* WIP
* fix service identities IAM example
* design principles
* toc anchors
* fix ordering
* style guide
* checks
* example tests
* tests and tools
* fix project example test
* address typos
* address comments
* address last comments
Suggest change of wording related to `terraform format`: should be done from the top, recursively, and after `pytest` step, because fixtures are also going to be checked for linting during PR.
