fix markdown syntax.

README.md

@@ -1,24 +1,31 @@
-
 eval
 ====
+
 [![Project Status: Active - The project has reached a stable, usable state and is being actively developed.](http://www.repostatus.org/badges/latest/active.svg)](http://www.repostatus.org/#active)
 [![docs](https://docs.rs/eval/badge.svg?version=0.4.0 "docs")](https://docs.rs/eval)
 
 Eval is a powerful expression evaluator.
 
-## [Document](https://docs.rs/eval)
+[Document](https://docs.rs/eval)
+--------------------------------
+
+Features
+--------
 
-## Features
 Supported operators: `!` `!=` `""` `''` `()` `[]` `,` `>` `<` `>=` `<=` `==`
 `+` `-` `*` `/` `%` `&&` `||` `n..m`.
 
 Built-in functions: `min()` `max()` `len()` `is_empty()` `array()`.
 
-## Where can eval be used?
+Where can eval be used?
+-----------------------
+
 * Template engine
 * ...
 
-## Usage
+Usage
+-----
+
 Add dependency to Cargo.toml
 
 ```toml
@@ -32,11 +39,12 @@ In your `main.rs` or `lib.rs`:
 extern crate eval;
 ```
 
-## Examples
+Examples
+--------
 
 You can do mathematical calculations with supported operators:
 
-```
+```rust
 use eval::{eval, to_value};
 
 assert_eq!(eval("1 + 2 + 3"), Ok(to_value(6)));
@@ -47,7 +55,7 @@ assert_eq!(eval("2 / 2 + 3 / 3"), Ok(to_value(2.0)));
 
 You can eval with context:
 
-```
+```rust
 use eval::{Expr, to_value};
 
 assert_eq!(Expr::new("foo == bar")
@@ -57,10 +65,9 @@ assert_eq!(Expr::new("foo == bar")
            Ok(to_value(true)));
 ```
 
-
 You can access data like javascript by using `.` and `[]`. `[]` supports expression.
 
-```
+```rust
 use eval::{Expr, to_value};
 use std::collections::HashMap;
 
@@ -73,10 +80,9 @@ assert_eq!(Expr::new("object.foos[1-1] == 'Hello'")
            Ok(to_value(true)));
 ```
 
-
 You can eval with function:
 
-```
+```rust
 use eval::{Expr, to_value};
 
 assert_eq!(Expr::new("say_hello()")
@@ -85,24 +91,24 @@ assert_eq!(Expr::new("say_hello()")
            Ok(to_value("Hello world!")));
 ```
 
-
 You can create an array with `array()`:
 
-```
+```rust
 use eval::{eval, to_value};
 
 assert_eq!(eval("array(1, 2, 3, 4, 5)"), Ok(to_value(vec![1, 2, 3, 4, 5])));
 ```
 
-
 You can create an integer array with `n..m`:
 
-```
+```rust
 use eval::{eval, to_value};
 
 assert_eq!(eval("0..5"), Ok(to_value(vec![0, 1, 2, 3, 4])));
 ```
 
-## License
+License
+-------
+
 eval is primarily distributed under the terms of the MIT license.
 See [LICENSE](LICENSE) for details.