Register language icon

I'm guessing this hasn't been done yet, but we can use this issue to coordinate steps taken. One of the first steps listed in [preparing for launch](https://exercism.org/docs/building/tracks/new/prepare-for-launch) is to open an issue to register an icon.

I'm guessing this counts as the [official icon](https://github.com/mlochbaum/BQN/blob/d6abe6879f53763bb1283a7721676be9e7f6c27c/logo.svg).

If there's nothing posted the next time I check on this issue, I'll go ahead and start the process to register this icon.

Start with the linked “preparing for launch” guidance, then inspect the referenced logo.svg to confirm which icon is being proposed. Check the registration process described there and document whether the official icon has been registered; the issue is done when that process is completed or its status is recorded.

Written by the indexing model from the issue text.