added state and wrapper illustrations

docs/The State Mechanism.ipynb

@@ -16,6 +16,8 @@
     "- operate on `States` and \n",
     "- return `States`.\n",
     "\n",
+    "<img src=\"https://autoresearch.github.io/autora/img/state_logic.png\" width=\"75%\" alt=\"State Logic\">\n",
+    "\n",
     "The `autora.state` submodule provides classes and functions to help build these functions. "
    ]
   },
@@ -327,7 +329,9 @@
    "source": [
     "### Use the `autora.state.on_state` decorator\n",
     "\n",
-    "`autora.state.on_state` is a wrapper for functions which allows them to accept `State` objects as the first argument.\n",
+    "`autora.state.on_state` is a wrapper for functions which allows them to accept `State` objects as the first argument. This decorator enables AutoRA components to retrieve relevant data from the state and add new data to it. \n",
+    "\n",
+    "<img src=\"https://autoresearch.github.io/autora/img/state_wrapper.png\" width=\"75%\" alt=\"State Wrapper Overview\">\n",
     "\n",
     "The most concise way to use it is as a decorator on the function where it is defined. You can specify how the \n",
     "returned values should be mapped to fields on the `State` using the `@autora.state.on_state(output=...)` argument."