Update README.md

Author: Zeioth

README.md

@@ -16,7 +16,7 @@ Neovim compiler for building and running your code without having to configure a
 - [How to install](#how-to-install)
 - [Available commands](#available-commands)
 - [Basic usage](#how-to-use-basic-usage)
-- [How to create a .solution file (advanced)](#how-to-create-a-solution-advanced)
+- [How to create a solution (advanced)](#how-to-create-a-solution-advanced)
 - [Make (advanced)](#make-advanced)
 - [FAQ](#faq)