Add troubleshooting guide for app stuck on 'Starting...' screen and c…

…larify external device connection requirements in FAQ.

docs/troubleshooting/faq.mdx

@@ -28,6 +28,11 @@ description: "Frequently Asked Questions"
   control.
 </Accordion>
 
+<Accordion title="My app is stuck on the 'Starting...' screen. What do I do?">
+  You might need to re-install the Poetry environment. In the `software`
+  directory, please run `poetry env remove --all` followed by `poetry install`
+</Accordion>
+
 <Accordion title="Can an 01 device connect to the desktop app, or do general customers/consumers need to set it up in their terminal?">
   We are working on supporting external devices to the desktop app, but for now
   the 01 will need to connect to the Python server.