Experiment BT support using Chrome web serial (#920)

* plumbing

* plumbing

* logging

* more notes

* fixing typing

* more plumbing

* more plumbing

* different baud rate

* talking to the brick

* first over the air drop

* fix buffer

* tweak paraetmers

* formatting fixing double upload

* reduce console.log

* cleanup

* add BLE button to download dialog

* changed label

* recover from broken COM port

* fix function call

* reduce log level

* adding ticks

* some help

* updated support matrix

* more docs

* updated browser help

* more docs

* add link

* add device

* added image

docs/SUMMARY.md

@@ -4,6 +4,7 @@
 
 * [Troubleshoot](/troubleshoot)
 * [EV3 Manager](https://ev3manager.education.lego.com/)
+* [Bluetooth](/bluetooth)
 * [Forum](https://forum.makecode.com)
 * [LEGO Support](https://www.lego.com/service/)
 * [FIRST LEGO League](/fll)