M3 Heat insert in AB-BN BOM needs detail updating

[simonrwatts]

@AaronHerrick BOM currently shows "M3x0.5 Heat set insert". This made me and others start searching. I had to search Discord for an answer.

Ideally it would read 'M3x5x4mm Heat Set insert (Same as Voron BOM)' to make it 100% clear :)

[AaronHerrick]

OK, I'll make the update

[FHeilmann]

Closing due to stale-ness and AB-BN being part of the official Voron ecosystem within SB