add a new target BLADE_F4

[hakrc1]

add a new target BLADE_F4

[mmosca]

Hi @hakrc1, good to see you want to submit a target.

Are you in contact with one of the developers already?

According to the hardware policy, we need at least 2 members of the dev team to receive samples for validation, before we can merge this as an official target.

Here is the link for the policy, in case you would like to have a look: https://github.com/iNavFlight/inav/blob/master/docs/policies/NEW_HARDWARE_POLICY.md

If you are not in touch with any devs, let me know and I can try to organize get you in touch with the right people.