refactor: include prerequisite step in the README

Signed-off-by: Ma1h01 <[email protected]>

trestle_sdk_examples/README.md

@@ -1,7 +1,31 @@
-# Trestle sdk examples
+# Trestle SDK examples
 
-A container for a set of simpler examples of using the trestle sdk.
+A container for a set of simpler examples of using the trestle SDK.
 
-## Creating a catalog
+## Prerequisites
+Download this repo
+
+```
+> cd
+> mkdir git
+> cd git
+> git clone https://github.com/oscal-compass/compliance-trestle-demos.git
+```
+
+Install compliance trestle, ideally in a python virtual environment.
+
+```
+> cd
+> python -m venv venv.compliance-trestle-demos
+> source venv.compliance-trestle-demos/bin/activate
+> cd git/compliance-trestle-demos
+> make install
+```
+
+## Running the demo
+```
+> cd trestle_sdk_examples
+> python create_a_catalog.py
+```
 
 Running `python create_a_catalog.py` will first try and fail to create a catalog (by failing to provide required attributes), then create a catalog, followed by writing it out to disk.