significant improvement to the readme and verification that all the examples work

examples/docker_instance.py

@@ -0,0 +1,26 @@
+import minerva
+from   minerva.docker import Docker
+import sys
+
+m       = minerva.Minerva("hay")
+pier    = m.pier(subnet_id = "subnet-05eb26d8649a093e1", # project-subnet-public1-us-east-1a
+                 sg_groups = ["sg-0f9e555954e863954",    # ssh
+                              "sg-0b34a3f7398076545"],   # default
+                 iam       = "S3+SSM+CloudWatch+ECR")
+
+mach = pier.machine(ami    = "ami-0b0cd81283738558a",  # ubuntu 22.04 x86
+             instance_type = "t3.medium",
+             username      = "ubuntu",
+             name          = f"minerva-aws-test")
+
+# Running the machine in the HAYSTAC PMO account
+# Pulling a container from the HAYSTAC T&E account
+d = Docker(machine   = mach,
+           #container = "436820952613.dkr.ecr.us-east-1.amazonaws.com/test:latest",
+           container = "amazon/aws-cli:latest",
+           variables = {"hello": "world"},
+           stdout    = sys.stdout)
+
+d.create()
+d.run("s3 ls")
+d.terminate()