Project browser integration: Design and add logo.png file [#3607805]

Based on the guidelines provided in the documentation Module Maintainers: How to update projects to be compatible with Project Browser - Logo:

Create a logo image file and add it to the project's repository.

Create a logo that is 512x512 square dimension in PNG format without animations. Suggested file size should be 10k or less. (Please note: you should not round the corners in the PNG itself or include the name of the module in the logo, unless there is some compelling branding reason.)

Use a lossy image tool (such as pngquant) to reduce file size while keeping the image quality at around 80%. Try to compress the file as much as possible, for example aim at ~8KB.

See examples of logo.png files in the modules listing:
https://www.drupal.org/project/project_module