docs(lib): fix several broken links throughout docs

Closes #1749
Closes #1750

src/body/mod.rs

@@ -7,7 +7,7 @@
 //!
 //! There are two pieces to this in hyper:
 //!
-//! - The [`Payload`](Payload) trait the describes all possible bodies. hyper
+//! - The [`Payload`](body::Payload) trait the describes all possible bodies. hyper
 //!   allows any body type that implements `Payload`, allowing applications to
 //!   have fine-grained control over their streaming.
 //! - The [`Body`](Body) concrete type, which is an implementation of `Payload`,

src/body/payload.rs

@@ -6,7 +6,7 @@ use super::internal::{FullDataArg, FullDataRet};
 
 /// This trait represents a streaming body of a `Request` or `Response`.
 ///
-/// The built-in implementation of this trait is [`Body`](Body), in case you
+/// The built-in implementation of this trait is [`Body`](::Body), in case you
 /// don't need to customize a send stream for your own application.
 pub trait Payload: Send + 'static {
     /// A buffer of bytes representing a single chunk of a body.

src/client/connect/dns.rs

@@ -2,9 +2,9 @@
 //!
 //! This module contains:
 //!
-//! - A [`GaiResolver`](GaiResolver) that is the default resolver for the
+//! - A [`GaiResolver`](dns::GaiResolver) that is the default resolver for the
 //!   `HttpConnector`.
-//! - The [`Resolve`](Resolve) trait and related types to build a custom
+//! - The [`Resolve`](dns::Resolve) trait and related types to build a custom
 //!   resolver for use with the `HttpConnector`.
 use std::{fmt, io, vec};
 use std::error::Error;

src/client/mod.rs

@@ -3,7 +3,7 @@
 //! There are two levels of APIs provided for construct HTTP clients:
 //!
 //! - The higher-level [`Client`](Client) type.
-//! - The lower-level [conn](conn) module.
+//! - The lower-level [`conn`](client::conn) module.
 //!
 //! # Client
 //!

src/server/mod.rs

@@ -6,7 +6,7 @@
 //! There are two levels of APIs provide for constructing HTTP servers:
 //!
 //! - The higher-level [`Server`](Server) type.
-//! - The lower-level [conn](conn) module.
+//! - The lower-level [`conn`](server::conn) module.
 //!
 //! # Server
 //!

src/service/mod.rs

@@ -1,10 +1,10 @@
 //! Services and MakeServices
 //!
-//! - A [`Service`](Service) is a trait representing an asynchronous function
-//!   of a request to a response. It's similar to
+//! - A [`Service`](service::Service) is a trait representing an asynchronous
+//!   function of a request to a response. It's similar to
 //!   `async fn(Request) -> Result<Response, Error>`.
-//! - A [`MakeService`](MakeService) is a trait creating specific instances of a
-//!   `Service`.
+//! - A [`MakeService`](service::MakeService) is a trait creating specific
+//!   instances of a `Service`.
 //!
 //! These types are conceptually similar to those in
 //! [tower](https://crates.io/crates/tower), while being specific to hyper.
@@ -16,8 +16,9 @@
 //! connection will receive.
 //!
 //! While it's possible to implement `Service` for a type manually, the helpers
-//! [`service_fn`](service_fn) and [`service_fn_ok`](service_fn_ok) should be
-//! sufficient for most cases.
+//! [`service_fn`](service::service_fn) and
+//! [`service_fn_ok`](service::service_fn_ok) should be sufficient for most
+//! cases.
 //!
 //! # MakeService
 //!