Add not.exist assertions not being supported

Author: jennifer-shehane

docs/api/commands/prompt.mdx

@@ -632,10 +632,11 @@ cy.prompt(electronicsFilterPrompt)
 
 | Limitation       | Details                                                                  |
 | ---------------- | ------------------------------------------------------------------------ |
-| Browser Support  | Chromium-based browsers only (Chrome, Edge, Electron)                    |
+| Authentication   | Requires Cypress Cloud account and/or valid record key                   |
 | Test Type        | E2E tests only (component testing not yet supported)                     |
-| Authentication   | Requires Cypress Cloud account or valid record key                       |
+| Browser Support  | Chromium-based browsers only (Chrome, Edge, Electron)                    |
 | Language Support | Optimized for English prompts; other languages are not guaranteed        |
+| Assertions       | 'not.exist' assertions are not supported                                 |
 | Command Coverage | Not all Cypress APIs supported - see [What you can do](#What-you-can-do) |
 
 ## Pricing & usage limits