Adding used by section

[bennyvasquez]

This is a draft for #488, but it's got problems.

• I can't get the logos to vertically center there, but I'm betting someone who's a bit CSS/HTML smarter than me will be able to make it happen very easily.
• These should be relatively small, just big enough to be easily seen.
• Adding this section here messes up all of the dark/light background patterns, so those will need to be adjusted.
• I haven't done any work on making it mobile friendly.
• I'd LOVE to see these scroll along.

[bennyvasquez]

@sboldyreva do you think you can take this across the finish line?

[sboldyreva]

@bennyvasquez let me take a look

[bennyvasquez]

Two more logos to add. Tried to just add them to the PR but my local version got messed up soooooooo.

[codyro]

Thanks @mattlasheboro for getting a version of the global layer logo done up.

[sboldyreva]

@bennyvasquez we can ask @Shone-Kristas to help with mobile version adjustments