Add shell.nix for Nix(OS) users

Nix-Shell.md

@@ -0,0 +1,17 @@
+# Nix Shell
+Nix development shells can be used to get development environments which can be accessed using the `nix-shell` command.
+
+Firstly, we must define a function. Nix expressions are written in a functional language (also called Nix) and use the function as their basic unit. This one takes a parameter called `pkgs` with a default value of the primary Nix package collection.
+```nix shell.nix+=
+{ pkgs ? import <nixpkgs> {} }:
+```
+
+Now, we can create a shell using the `pkgs.mkShell` function. This function creates the shell that will be accessed and defines properties of it. In our case, we use the `buildInputs` parameter to include our build dependencies (ie. Golang) in this shell.
+```nix shell.nix+=
+pkgs.mkShell {
+  buildInputs = with pkgs; [ go ];
+}
+```
+
+# About Nix
+Nix is a package manager designed to allow for completely reproducible builds. It allows for developers to ensure that software builds the same on 1 computer as it does on any other. For more information, see <https://nixos.org/>.

README.md

@@ -24,6 +24,9 @@ directory. You can use the `-o $path` argument to `go build` to build
 the binary in a different location. (i.e. `go build -o ~/bin/` to put the
 binary in `~/bin/`.)
 
+#### A note for Nix(OS) users
+This repo also comes with a `shell.nix` file. While an existing version is included, like lmt itself, this is mainly for bootstrapping purposes. To compile it, use `lmt Nix-Shell.md`
+
 ## Demo
 
 To observe `lmt` at work, put this file in an empty directory, cd to that

shell.nix

@@ -0,0 +1,4 @@
+{ pkgs ? import <nixpkgs> {} }:
+pkgs.mkShell {
+  buildInputs = with pkgs; [ go ];
+}