docs(TSP-1448): document Invent resource panel (new-chat state) - #820

Running Vale across on the following files affected by this PR:

- build/invent/invent.mdx
- get-started/chat/using-agents.mdx
- integrations/add-integrations.mdx

Attempting to initialize Vale linter...
No customer vale configuration detected. Using Mintlify's default configuration.
Attempting to run Vale spellcheck...
Vale spellcheck completed successfully.

build/invent/invent.mdx:
	- 30:44    Did you really mean 'Evals'?
	- 92:5     Did you really mean 'Invent's'?

get-started/chat/using-agents.mdx:
	- 10:33    Did you really mean 'Invent's'?


Found 3 suggested changes across 2 files in 525.15ms