[Design] Brand Guide for Certification Badge usage

[lixuna]

Describe the update: Create Brand Guide for CNTI Certification logo and badge

• similar to https://github.com/cncf/artwork/tree/master/other/certified-cnf and https://github.com/cncf/artwork/blob/main/other/certified-cnf/certified-cnf-brand-guide.pdf

Describe why update is needed

• CNF WG (and CNCF’s related Cloud Native Telco efforts) has moved to LFN (see wiki)

Tasks

• [ ] blocked by #68
• [ ] request assistance from design team to update https://github.com/cncf/artwork/tree/master/other/certified-cnf for CNTI Certification