docs: add commands to architecture doc

Signed-off-by: chenk <[email protected]>

ARCHITECTURE.md

@@ -8,6 +8,7 @@ The directory structure is broken down as follows:
 
 - `cmd/` - These CLI tools are primarily used during development for end-to-end testing without needing to pull the library into trivy/tfsec etc.
 - `checks` - All of the checks are defined in this directory.
+- `commands` - All Node-collector commands are defined in this directory.
 - `pkg/spec` - Logic to handle standardized specs such as CIS.
 - `pkg/rules` - This package exposes internal rules, and imports them accordingly (see _rules.go_).
 - `specs/` - Standaridized compliance specs such as CIS.