Get and build prompt from local JSON file

Here we map our AI actions to the prompt from the JSON file
to be able to use them.

scribe/test/assets/test_prompts.json

@@ -0,0 +1,30 @@
+{
+  "prompts": [
+    {
+      "name": "test-prompt",
+      "messages": [
+        {
+          "role": "system",
+          "content": "You are a test assistant."
+        },
+        {
+          "role": "user",
+          "content": "INSTRUCTION:\nTest instruction.\n\nTEXT:\n{{input}}"
+        }
+      ]
+    },
+    {
+      "name": "test-prompt-with-task",
+      "messages": [
+        {
+          "role": "system",
+          "content": "You are a test assistant with task."
+        },
+        {
+          "role": "user",
+          "content": "INSTRUCTION:\n{{task}}\n\nTEXT:\n{{input}}"
+        }
+      ]
+    }
+  ]
+}