Create troubleshooting page in docs

[waldekmastykarz]

To help customers troubleshoot proxy not working as intended, we should create a page to which we can point to in-product, from issues, on social, etc.

The page should contain walk customers through the same troubleshooting steps that we'd take if we're to help them 1:1. Proposed structure:

Symptom: Proxy is not intercepting requests

• no requests intercepted
  • is proxy running
  • is it registered as system proxy
  • Have you configured correct url to watch
  • Are you using the right config file
  • Are you using proxy with a Node app
  • Are you using proxy with PowerShell on Windows

Symptom: Requests intercepted but passed through

Symptom: You get an SSL error in your app when using Dev Proxy:

• Do you have the proxy cert installed
• Is it trusted