suggestions for the adopter request form

Created by: joespeed

a few suggestions for the adopter request form: https://github.com/EclipseFdn/iot.eclipse.org/issues/new?template=adopter_request.md

1. should say "svg or png"
2. should say "zipped if svg" since GitHub form doesn't support svg file type.
3. should make it clear the logo should be with a transparent background. I noticed issues over and over of people uploading black logos with white backgrounds.

Maybe something like this? Important: Please attach your logos in svg or png format, zipped if svg.

• We need color logo with transparent background.
• We also need white logo with a transparent background.