adding illustrations/logos/fastify

Purpose

First of all, I had to do it via fork because I was not allowed to push even in a separate branch. Purpose: Add Fastify SVG to Template I created > https://gitlab.com/fmorais-templates/fastify-typescript-prisma-swagger-cockroachdb-api-template

Checklist

For a new icon and/or illustration:

• Link to related design issue:
• If this adds an icon ensure that it follows the new icon checklists.
• If this adds an illustration ensure that it follows the new illustration checklists.

For third-party trademarks:

• If this adds or updates an icon or illustration that includes a third-party trademark, ensure that it follows the process for adding third-party trademarks to GitLab.