[Landscape] Table heading text is too low contrast in light mode

[leecalcote]

Current State:
https://layer5.io/service-mesh-landscape

Desired State:
High contrast text and background in both light and dark modes.

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Contributor Resources

• Instructions for updating the landscape
  The layer5.io website uses Gatsby, React, and GitHub Pages. Site content is found under the master branch.
• See contributing instructions
• See Layer5 site designs in this Figma project.

[vr-varad]

hey @leecalcote I could work on this

[miacycle]

Thank you, @vr-varad 👍