Add BLM solidarity statement

[isaacdurazo]

@vladikoff Here's my PR per discussed in issue #218. I would appreciate a code review on this 😃

This is how the banner looks in every page

Here's a dedicated page for the Black Lives Matter Statement

[jsf-clabot]

All committers have signed the CLA.

[vladikoff]

deploying!

[vladikoff]

Thanks @isaacdurazo !!!

[isaacdurazo]

Thank you so much for the help @vladikoff 🙌