message: [docs] mention nix-shell and fix spelling
diff: @@ -13,9 +13,11 @@ Executable: `surelog`
  * `sudo apt-get install build-essential cmake git pkg-config tclsh swig uuid-dev libgoogle-perftools-dev python3 python3-dev`
  - * If you don't intent to change the grammar: `sudo apt-get install default-jre`
  + * If you don't intend to change the grammar: `sudo apt-get install default-jre`
  - * If you do intent to change the grammar: `sudo apt-get install default-jdk ant`
  + * If you do intend to change the grammar: `sudo apt-get install default-jdk ant`
  +
  + * In a [nix environment](https://nixos.org) simply type `nix-shell` to set up the dependencies.
  * If you have a version of cmake before 3.13 on your system
  (check with `cmake --version`), you need get a version that is more current.
  