Adjust Bananapi WiKi Pages

Changed, awaiting approval from Bpi

Uploaded the logo and desktop image, waiting for mod approval from bpi part

Text:
Armbian is a simple, light, and fast Linux operating system optimized for development boards, offering a user-friendly experience for newcomers and professionals. The system is designed to minimize SD card wear. It can be accessed via serial, HDMI/VGA, or SSH, with optional special utilities available for further customization. The system can also be built and customized via the armbian build utility.

On the page where Armbian is mentioned, there are some links to unofficial images with kernel 6.0.y made by vendor. I would suggest to remove those as they are useless now. Also add some logo and welcome screen and expand text to what Armbian offers. Also put a link to SDK