Clarify that this is not `node-postgres` (on npm)?

[mmkal]

Hi - I just created https://github.com/fuxingZhang/postgres/issues/2 because for the Nth time I accidentally went to the wrong npm package.

I wonder if this library should just stop referring to itself as node-postgres, since the way users install is npm install pg, and not npm install node-postgres. I know the website is node-postgres.com but uhh maybe that could eventually not be the case either.