Fix redundent docs and CLI help text

docs/development/custom_commands.md

@@ -73,11 +73,7 @@ rather than in MVT's own `config.yaml`.
 
 ### Commands on `mvt`
 
-The `mvt` command hosts what belongs to neither platform: `version`,
-`completion`, `plugins` and `download-iocs`. A plugin command which is not
-about the acquisition of one platform, such as one which configures the plugin
-or synchronizes the indicators it uses, belongs there too, in the
-`mvt.cli_plugins` group:
+A MVT plugin command can also add sub-commands to the base `mvt` command. This can be used for commands which are not tied to a particular forensic platform:
 
 ```toml
 [project.entry-points."mvt.cli_plugins"]

src/mvt/cli.py

@@ -47,10 +47,8 @@ CONTEXT_SETTINGS = dict(help_option_names=["-h", "--help"])
 def cli(ctx, disable_update_check, disable_indicator_update_check, verbose):
     """Mobile Verification Toolkit.
 
-    mvt-ios and mvt-android run the forensic analysis of an acquisition: each
-    provides the check-* commands of its platform. This command hosts what
-    belongs to neither platform; run it without a command to see the installed
-    version and the list of what it offers.
+    The 'mvt-ios' and 'mvt-android' CLI commands are used to perform
+    forensic analysis on IOS and Android devices.
     """
     ctx.ensure_object(dict)
     ctx.obj["disable_version_check"] = disable_update_check