Default Remote Write Endpoint is Difficult to Find

[GLStephen]

There is documentation of config vars, a series of blog posts and a page dedicated to aspects of the functionality. However, the actual default endpoint of "/api/v1/write" is in a glossary item or something similar. I'm happy to make a PR, but not sure where this should be, but it and its configurability should be more prominent.

[SuperQ]

It should be in the http API section. That documentation is in the prometheus repo. But some additional cross linking would be appreciated.