Update docs for CLI

docs/documentation/CLI.md

@@ -1,2 +1,32 @@
 # CLI
 ::: carbontracker.cli.main
+<line>
+### Usage
+
+To start tracking, simply run the following command:
+
+```bash
+carbontracker <script_or_command> <arg1> <arg2> --log_dir <log_directory> --api_keys <api_keys>
+```
+For example:
+```bash
+carbontracker python train_resnet.py --epochs 100 --step_size 1 --log_dir ./logs --api_keys '{"electricitymaps": "YOUR_KEY_HERE"}'
+```
+
+### Arguments
+
+- `--log_dir`: Specifies the directory where CarbonTracker will save the logs. This is useful for keeping a record of your runs and for later analysis.
+- `--api_keys`: API key(s) for external services used by CarbonTracker to retrieve real-time carbon intensity data. Currently, [Electricity Maps](https://www.electricitymaps.com/) is supported
+
+### Additional Options
+Log Parsing: If you've previously run CarbonTracker and saved the logs, you can parse and aggregate the data for analysis. Use the following command to aggregate logs from a specific directory:
+```bash
+carbontracker --parse <log_directory>
+```
+For example:
+
+```bash
+carbontracker --parse ./logs
+```
+
+