docs: add raw parameter bindings scenario

[khoaHyh]

Addresses: https://github.com/knex/knex/issues/6016

I've run into this and took me a lot of searching to find a solution. I've also seen many threads about it so I thought I'd add this in to save someone else the trouble.

Edit: Also found this https://github.com/knex/knex/issues/1537#issuecomment-281888969 which is much more elegant

[rluvaton]

The website repo has been moved inside the https://github.com/knex/knex repo. Please open a PR there instead: (the website will be under the docs folder)