Update icons

Author: savannahostrowski

media/icons/fastapi-walkthrough.svg

@@ -114,7 +114,7 @@
         {
           "id": "fastapi",
           "title": "FastAPI",
-          "icon": "media/icons/fastapi.svg"
+          "icon": "media/icons/logo-white.svg"
         }
       ]
     },
@@ -123,7 +123,7 @@
         {
           "id": "endpoint-explorer",
           "name": "Endpoint Explorer",
-          "icon": "media/icons/fastapi.svg"
+          "icon": "media/icons/logo-white.svg"
         }
       ]
     },
@@ -138,7 +138,7 @@
         "id": "fastapi-getting-started",
         "title": "Get Started with FastAPI",
         "description": "Learn how to use the FastAPI extension to boost your productivity",
-        "icon": "media/icons/fastapi-walkthrough.svg",
+        "icon": "media/icons/logo-teal.svg",
         "steps": [
           {
             "id": "view-endpoints",