Multi asset Simulations (#22)

* Prototype multi-asset market

* Additional market tests

* Add docstrings

* Better const naming

* Prototype multi-asset environment

* Cleanup macros and add multi-asset agent trait

* Implement multi-asset sim runner

* Implement agents for market

* Update examples

* Update docstrings

* Add example to pre-merge checks

.github/workflows/pre_merge.yaml

@@ -20,10 +20,12 @@ jobs:
           run: cargo fmt --all -- --check
         - name: Clippy
           run: cargo clippy -- -Dwarnings
-        - name: Random stepped example
+        - name: Random discrete-event example
           run: cargo run --example random_agents
         - name: Order book example
           run: cargo run --example order_book
+        - name: Multi-asset example
+          run: cargo run --example multi_asset
         - name: Build docs 📚
           run: cargo doc --no-deps