Added docs link and shield

Author: grossws

Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 authors = ["Konstantin Gribov <grossws@gmail.com>"]
 
 repository = "https://github.com/smbc-rs/smbc"
+documentation = "https://docs.rs/smbc"
 license = "GPL-3.0+"
 keywords = ["smbclient", "samba", "cifs"]
 description = "type-safe libsmbclient wrapper with std::fs-like interface"

README.md

@@ -3,6 +3,7 @@
 [![Crates.io](https://img.shields.io/crates/v/smbc.svg)](https://crates.io/crates/smbc)
 [![Build Status](https://travis-ci.org/smbc-rs/smbc.svg?branch=master)](https://travis-ci.org/smbc-rs/smbc)
 [![Crates.io](https://img.shields.io/crates/l/smbc.svg)](https://crates.io/crates/smbc)
+[![Docs](https://docs.rs/smbc/badge.svg)](https://docs.rs/smbc)
 
 ## About