chore: Add SaaS template to trpc

[johnsicili]

Adding new template to the dashboard. Getting this queued up and will coordinate with someone to add to .env, though it's okay if this goes out first.

SaaS Landing
5b33acf4-53cf-4f03-8973-d5679772edee

Description

1. What is this PR about (link the issue and add a short description)

Steps for reproduction

1. click button
2. expect xyz

Code Review

• hi @kof, I need you to do
  • conceptual review (architecture, feature-correctness)
  • detailed review (read every line)
  • test it on preview

Before requesting a review

• made a self-review
• added inline comments where things may be not obvious (the "why", not "what")

Before merging

• tested locally and on preview environment (preview dev login: 0000)
• updated test cases document
• added tests
• if any new env variables are added, added them to .env file