* Properly tag instances and subnets with `kubernetes.io/cluster/$cluster_name`

This is required by kubernetes to support multiple clusters in a single vpc/az

* Get rid of loadbalancer_apiserver_address as it is no longer needed

* Dynamically retrieve aws_bastion_ami latest reference by querying AWS rather than hard coded

* Dynamically retrieve the list of availability_zones instead of needing to have them hard coded

* Limit availability zones to first 2, using slice extrapolation function

* Replace the need for hardcoded variable "aws_cluster_ami" by the data provided by Terraform

* Move ami choosing to vars, so people don't need to edit create infrastructure if they want another vendor image (as suggested by @atoms)

* Make name of the data block agnostic of distribution, given there are more than one distribution supported

* Add documentation about other distros being supported and what to change in which location to make these changes

* Point apiserver address to 0.0.0.0
Added loadbalancer api server address
* Update documentation

This trigger ensures the inventory file is kept up-to-date. Otherwise, if the file exists and you've made changes to your terraform-managed infra without having deleted the file, it would never get updated. 

For example, consider the case where you've destroyed and re-applied the terraform resources, none of the IPs would get updated, so ansible would be trying to connect to the old ones.

Rewrote AWS Terraform deployment for AWS Kargo. It supports now
multiple Availability Zones, AWS Loadbalancer for Kubernetes API,
Bastion Host, ...

For more information see README