Add logo and rewrite description

Problem/Motivation

With project browser being released, it would be great to revise module description, logo and overall presentation.

Steps to reproduce

Visit https://www.drupal.org/project/votingapi_reaction →

Proposed resolution

Update logo, rewrite description in the README file and copy it over to project description in Drupal.org. Also maybe a better screenshot with Drupal CMS.

Remaining tasks

- New logo
- Updated description in the README
- Updated description in the project page on Drupal.org
- Better screenshots