♿️(nix) Added nix-shell file with dependencies

Added `docker`, `docker-compose` and `gnumake` as dependencies for a dev
environment for nix users

While `docker` and `docker-compose` are not needed in shell.nix if the
user has docker enabled, if docker daemon is not enabled system-wide,
these programs will warn the user, insted of saying they are not
installed.

Author: PedroManse

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to
 
 ## Added
 
+- ♿️(nix) Added nix environment declaration #751
 - ✨(frontend) add pinning on doc detail #711
 - 🚩(frontend) feature flag analytic on copy as html #649
 - ✨(frontend) Custom block divider with export #698

shell.nix

@@ -0,0 +1,9 @@
+{ pkgs ? import <nixpkgs> {} }:
+pkgs.mkShellNoCC {
+    nativeBuildInputs = with pkgs.buildPackages; [
+			docker
+			docker-compose
+			gnumake
+		];
+}
+