fix header level

README.md

@@ -25,7 +25,7 @@ A curated list of awesome Rust code and resources. Inspired by the other [awesom
 
 * [alexcrichton/rust-compress](https://github.com/alexcrichton/rust-compress) — compression algorithms written in Rust [<img src="https://travis-ci.org/alexcrichton/rust-compress.png?branch=master">](https://travis-ci.org/alexcrichton/rust-compress)
 
-## Computation
+### Computation
 * [eholk/rust-opencl](https://github.com/eholk/rust-opencl) — [OpenCL](https://www.khronos.org/opencl/) bindings [<img src="https://travis-ci.org/eholk/rust-opencl.png?branch=master">](https://travis-ci.org/eholk/rust-opencl)
 
 ### Cryptography