(frontend) closes #180; add documentation for using CLI

site/content/docs/usage/_index.md

@@ -1,6 +1,6 @@
 ---
 title: Usage
 ---
-TBA.
+WIP (Work In Progress).
 
-While you wait; watch the [official demo video](https://youtu.be/rwL99Ac5g98).
+- Watch the [official demo video](https://youtu.be/rwL99Ac5g98).

site/content/docs/usage/cli.md

@@ -0,0 +1,29 @@
+---
+title: CLI
+---
+
+## How To Access
+### Docker Install
+Access from the official Docker image is easy! We can just use the "exec" command from either "docker" or "docker compose".
+
+Example based off install guide:
+
+```sh
+docker compose exec note-mark /note-mark --help
+```
+
+#### Notes
+Due to using a distro-less base image interactive tty sessions with a shell (sh, bash) are not possible.
+
+### Bare Install
+Assuming all of the environment variables are already set and Note Mark is accessible from path:
+
+```sh
+note-mark --help
+```
+
+## Available Commands
+- `serve`: run the web API server, depending on install method may include UI
+- `clean`: remove old and unused data
+- `user`: add, remove and change user passwords
+- `help`: shows the help for CLI