Add OpenAI ChatGPT

[davidcapling-article]

What is the vendor's name?
OpenAI

What is the vendor's pricing site?
https://openai.com/chatgpt/pricing

What is the base pricing? Use the lowest tier that looks sane for a small business customer, not free or personal tiers.
$25/User/Month

What is the minimum pricing for SSO support?
Enterprise tier (please request pricing, massive waitlist)

Does this pricing info come from a quote or other non-public source?
"Other List" Contender, as enterprise pricing is not public and also involves a massive waitlist (3+ months so far!)

Are there any caveats we should list in the footnotes?

[MMore]

Hey @davidcapling-article and @Mike-0000.

Thank you for your contribution! I just integrated your PR into https://github.com/ssotax/ssotax as this repository was not maintained for a long time. Your changes are in ssotax/ssotax@5efcdbb.

You find the new page under https://ssotax.org/. I also made a few improvements based on community feedback like showing free SSO providers. Feel free to share your feedback!