typo

README.md

@@ -49,9 +49,11 @@ x^9+6x^7-3x^6+12x^5-12x^4+11x^3-12x^2+6x-1
 
 You need Rust programming language environment (works with stable, beta and nighly channels).
 If you don't have already installed please use [rustup.rs](https://www.rustup.rs) to easily
-install the complete environment. Than, you can install packaged version from the crates.io
+install the complete environment. Then you can install packaged version from the crates.io
 using `cargo install xxcalc --features interactive`.
 
+#### Compilation
+
 The basic compilation process from the source is just running `cargo` in command line:
 
 ```bash