Accessibility: several color contrast issues on home page

[ashleemboyer]

Description

Here are some color contrast issues found with both manual inspection and axe browser extension:

• GitHub, Discord, YouTube, etc. icons in header: The color of these icons in their base state does not have sufficient contrast with the background color.
  • WebAIM Color Contrast comparison
  • WCAG 2.1 SC 1.4.11 Non-text Contrast (AA) details about graphical objects
• "Chakra UI is a simple..." p text after h1
• "Get Started" CTA with #ffffff on #319795 background
• "See showcase" CTA with #ffffff on #319795 background
• "We're dedicated to..." with #c1e0df on #319795 background
• "Downloads per month", "GitHub stars", etc. stats with #ffffff on #319795 background
• "CHAKRA HEROES" text with #ffffff on #319795 background

There are several more in the same styles and types of components, these are just a few.