CLI: unclear classification of commands

### Version Information

CLI Version (for CLI related issue): DDN CLI Version: v1.0.0

### What is the current behaviour?

Currently cli classifies commands under the following sections:
```
Usage:
ddn [flags]
ddn [command]

DDN operations
project Manage Hasura DDN Project

Metadata operations
command Perform Command related operations
connector Perform Connector related operations
connector-link Perform DataConnectorLink related operations
model Perform Model related operations
subgraph Perform Subgraph related operations
supergraph Perform Supergraph related operations

Authentication operations
auth Manage Hasura DDN CLI Auth

Other operations
codemod Perform transformations on your Hasura project directory
context Perform context operations
help Help about any command
plugins Manage plugins for the CLI
update-cli Update this CLI to the latest version or to a specific version
version Prints the CLI version
```

Its unclear what `DDN operations` and `Metadata operations` are without additional context.

Example of confusing behaviour:
- `supergraph` is not listed under `DDN operations`, but we can do `ddn supergraph build apply` which "Applies a SupergraphBuild to its Project **on Hasura DDN**".