Tell the user that they must always enter 'bluetooth mode' to flash a micro:bit

[dnlbaines]

This commit adds a new dialog that prompts the user to enter bluetooth mode when flashing the micro:bit if they have not done so already (and the hex they are using requires it). It also changes the samples.zip extraction to a much faster method.

Minor changes:

• samples.zip was modified to remove an OS X folder
• Updated the create code/my scripts buttons to link directly to makecode
• Updated the bluetooth mode text based on a suggestion from @jaustin

[microbit-sam]

Hey Daniel,

Can you remind me of the steps required to trigger the warning you've added?

I thought we were catching the scenario where user has reflashed the micro:bit and hasn't repaired, but I've not managed to trigger your pop up.. flashing worked from 'makecode app' mode

[dnlbaines]

Hey Daniel,

Can you remind me of the steps required to trigger the warning you've added?

I thought we were catching the scenario where user has reflashed the micro:bit and hasn't repaired, but I've not managed to trigger your pop up.. flashing worked from 'makecode app' mode

It should trigger if you have previously paired the micro:bit in the app but haven't entered bluetooth mode when you try to flash (and the hex is not one that does not require you to enter bluetooth mode).

[microbit-sam]

Right, so I think this also wants to cover when you try to connect to a micro:bit that you've flashed over USB since pairing

I've just tried USB flashing, pairing, USB flashing, then connecting in app mode
This fails with Error: Please reset your micro:bit and try again

In this situation the micro:bit needs to be re-paired, as the USB flash has removed the bond info that was stored in the flash