Add developer surveys to key pages

[josephjclark]

We are currently developing a series of developer surveys aimed at getting feedback about various tools, like the CLI.

I expect we'll want surveys for the CLI, VSCode, and at least one for Lightning.

We should add a link to these surveys on particular pages of the docsite.

We could embed it as a tip or info boxout at the top of some docs pages:

Or we could make it a banner at the top of the page (but within the contents). Maybe make it dismissable too.

Maybe we can use Posthog, if we can target it to certain pages and make it not too annoying?