Better explain environment variables

Signed-off-by: Daniel J Walsh <[email protected]>

ramalama/cli.py

@@ -69,10 +69,29 @@ def use_container():
 
 
 def init_cli():
+    description="""\
+On first run RamaLama inspects your system for GPU support, falling back to CPU
+support if no GPUs are present. RamaLama uses container engines like Podman or
+Docker to pull the appropriate OCI image with all of the software necessary to
+run an AI Model for your systems setup. This eliminates the need for the user
+to configure the system for AI themselves. After the initialization, RamaLama
+will run the AI Models within a container based on the OCI image.\n
+
+RamaLama first pulls AI Models from model registires. It then start a chatbot
+or a service as a rest API from a simple single command. Models are treated
+similarly to the way that Podman or Docker treat container images.
+
+If you have both Podman and Docker installed, RamaLama defaults to Podman, use
+the `RAMALAMA_CONTAINER_ENGINE=docker` environment variable to override this
+behaviour.
+
+RamaLama supports multiple AI model registries types called transports. Supported transports:
+
+"""
     parser = ArgumentParser(
         prog="ramalama",
         formatter_class=argparse.ArgumentDefaultsHelpFormatter,
-        description="Simple management tool for working with AI Models.",
+        description = description,
     )
     parser.add_argument("--store", default=get_store(), help="store AI Models in the specified directory")
     parser.add_argument(
@@ -84,7 +103,7 @@ def init_cli():
         dest="container",
         default=use_container(),
         action="store_true",
-        help="run RamaLama in the default container",
+        help="run RamaLama in the default container. The RAMALAMA_IN_CONTAINER environment variable modifies default behaviour.",
     )
     parser.add_argument(
         "--image",
@@ -96,7 +115,7 @@ def init_cli():
         dest="container",
         default=False,
         action="store_false",
-        help="do not run RamaLama in the default container",
+        help="do not run RamaLama in the default container. The RAMALAMA_IN_CONTAINER environment variable modifies default behaviour.",
     )
     parser.add_argument(
         "--runtime",