[Feature] add text only testimonials to landing page

[lixuna]

MVP version of #16

Is your feature request related to a problem? Please describe.

• in addition to adding the certified products to the landing page, cncf/cnf-certification#14, and adding a section for supporting organizations (CSPs) #15 , we could also add an area for Proof Points and/or Testimonials to be displayed on the landing page

Describe the solution you'd like

• Create a new section for Testimonials on the landing page
• Display the Testimonials text

[lixuna]

[lixuna]

This enhancement was added to https://www.cncf.io/certification/cnf/#testimonials on Jul 21, 2022