In download, make "by Manufacturer" clickable to search other board.

My enhancement proposal:

On a board download page like https://circuitpython.org/board/raspberry_pi_pico/ you see the board name and manufacturer:
```
Pico
by Raspberry Pi
```
Make the `by Manufacturer` (or only `Manufacturer`) clickable and going to the page that list all the board from that manufacturer: https://circuitpython.org/downloads?manufacturers=Raspberry+Pi
