Consider updating Express integration docs to use `express.json()` instead of `body-parser`

[glasser]

Huh, apparently for 5 years (since v4.16.0) you can do express.json() instead of also installing body-parser. Maybe we should do that in the standalone server and in our docs around using expressMiddleware.

On the other hand, perhaps it's nicer to directly depend on your dependencies so you can get bug fixes via direct upgrades rather than transitive upgrades, so maybe we should leave it as is.

See https://community.apollographql.com/t/is-it-necessary-to-install-bodyparser/5163

[trevor-scheer]

I prefer the latter, though not opposed to documenting express.json as a simpler-but-not-our-preference option.

[glasser]

I ended up doing this as part of the Express v5 support work. Most docs these days do seem to encourage express.json() and it's fewer dependencies to install.