Try to get better list of boards

[halamix2]

• list is dynamically generated, prints all boards, grouped by architecture, sorted by the board's ID
• move header outside of the architecture loop

example (tested with local crafted JSON file)

  Board                SOC        Name                
arm
===
  boneblack            AM335x     BeagleBone Black    
  libre_all_h3         H3         Libre Computer Board ALL-H3-CC
  nanopi_neo           H3         NanoPi Neo          
  odroid_xu3           Exynos5    ODROID XU3/XU4/HC1/HC2
  orangepi_one         H3         OrangePi One        
  rpi2                 BCM2836    Raspberry Pi 2      
  rpi3                 BCM2837    Raspberry Pi 3      
  rpi4                 BCM2711    Raspberry Pi 4      
  tinkerboard          RK3288     Asus Tinkerboard    
arm64
===
  orangepi_zero2       H616       OrangePi Zero2      
weird
===
  weird                weird32    WeirdBoard 3000     

I have zero experience with Rust, feel free to make this better :)

• Task defined in Don't hardcode manifest URL in two places #3 (comment)