Make existing docs more consistent (#2307)

* opening and closing links

* sudo example compiles

* add Aura after it was merged to master

* remove extern crate line

substrate/srml/contract/src/lib.rs

@@ -17,7 +17,9 @@
 //! # Contract Module
 //!
 //! The Contract module provides functionality for the runtime to deploy and execute WebAssembly smart-contracts.
-//! To use it in your runtime, you need to implement the [`contracts::Trait`](./trait.Trait.html).
+//!
+//! - [`contract::Trait`](./trait.Trait.html)
+//! - [`Call`](./enum.Call.html)
 //!
 //! ## Overview
 //!
@@ -61,12 +63,6 @@
 //! This creates a new smart contract account and calls its contract deploy handler to initialize the contract.
 //! * `call` - Makes a call to an account, optionally transferring some balance.
 //!
-//! See the [`Call`](./enum.Call.html) enum and its associated variants for details of each function.
-//!
-//! ### Public functions
-//!
-//! See the [`Module`](./struct.Module.html) struct for details on publicly available functions.
-//!
 //! ## Usage
 //!
 //! The Contract module is a work in progress. The following examples show how this Contract module can be
@@ -77,7 +73,7 @@
 //!
 //! ## Related Modules
 //!
-//! * [`Balances`](../srml_balances/index.html)
+//! * [Balances](../srml_balances/index.html)
 
 #![cfg_attr(not(feature = "std"), no_std)]