Micro USB UART connector easily breaks on explorer board

[PieterGit]

I wrote a guide how to fix the Explorer board if the micro usb connectors came off.
If others have success or failed, please use this issue to report.

[PieterGit]

Pull request for oref0 docs can be found here: openaps/docs#1193

While the PR has not been merged, a rendered version can be found here: https://github.com/PieterGit/docs/blob/201801_microusb/docs/docs/Troubleshooting/Edison-hardware-troubleshooting.md