Update BLMSolidarityModal to remove inline styles #178
Description
The BLMSolidarityModal uses extensive inline styles. Instead, we can use classes to add styling to this component and remove redundancy.
The BLMSolidarity component exists in this file: https://github.com/tlsaeger/ml5-website/blob/e65a41f90078e26c940eb4c8c90d6d7466156060/src/templates/home-page.js