chore: update to version 3.2.0 and clean up readme a bit

Author: ctron

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "colored_json"
-version = "3.1.0"
+version = "3.2.0"
 edition = "2018"
 authors = ["Jens Reimann <jreimann@redhat.com>", "Harald Hoyer <harald@redhat.com>"]
 description = "Colorize JSON, for printing it out on the command line"

README.md

@@ -14,8 +14,6 @@ colored_json = "3"
 And then color your JSON output:
 
 ~~~rust
-extern crate colored_json;
-
 use colored_json::prelude::*;
 
 fn main() -> ::std::result::Result<(), Box<::std::error::Error>> {
@@ -40,8 +38,6 @@ fn main() -> ::std::result::Result<(), Box<::std::error::Error>> {
 Or directly write it out:
 
 ~~~rust
-extern crate serde_json;
-extern crate colored_json;
 use serde_json::{from_str, Value};
 use std::io::stdout;
 use std::io::Write;