Document alternative to shortcut when opening developper console on linux in the desktop app

[f8thl3ss]

In some cases, on linux, the shortcut Ctrl + shift + I doesn't work to open the console. We should document here https://docs.caido.io/app/troubleshooting/report_bug.html#frontend-logs that it's possible to open the console by pressing alt to open the menu bar, then click on View, then Toggle Developper Tools