docs: add additional intro to basic usage

docs/cli/basic-usage/README.md

@@ -1,7 +1,33 @@
-# Command Line Interface Overview
+# Command Line Interface Basic Usage
 
 The command line interface allows us to load and save `States` and run arbitrary functions on them.
 
+You can use the command line interface if the following conditions are true:
+
+1. Every part of `s` can be successfully [pickled](https://docs.python.org/3/library/pickle.html).
+2. You can write each step of your experiment as a single importable function which operates on a state and returns 
+   a state:
+    ```python
+    from example.lib import initial_state, experimentalist, experiment_runner, theorist
+    s = initial_state()
+    for i in range(3):
+        s = experimentalist(s)
+        s = experiment_runner(s)
+        s = theorist(s)
+    ```
+
+Often, different parts of AutoRA experiments require very different computational resources. For instance:
+- The theorist and experimentalist might require training or use of neural networks, and benefit from high 
+  performance computing (HPC) resources for short bursts – minutes or hours.
+- The experiment runner might post an experiment using a service like "Prolific" and poll every few minutes for 
+  hours, days or week until the experimental data are gathered.
+
+Running the experiment runner with the same resources as the theorist and experimentalist in this case would be 
+wasteful, and may be prohibitively expensive.
+
+To solve this problem, AutoRA comes with a command line interface. This can be used with HPC schedulers like [SLURM]
+(https://slurm.schedmd.com/) to run different steps in the cycle with different resources.
+
 ## Setup
 
 To use the command line, we first define a package `example` containing the functions we want to run on the State: