Add troubleshooting doc how to solve SessionHandler::read() error based on orchestral/platform#35.

Signed-off-by: crynobone <crynobone@gmail.com>
Tweak formatting.

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.0' into 2.1

Signed-off-by: crynobone <crynobone@gmail.com>

Conflicts:
	src/troubleshoot.md