nix-build: add page

pages/common/nix-build.md

@@ -0,0 +1,12 @@
+# nix-build
+
+> Build a Nix expression.
+> More information: <https://nixos.org/releases/nix/latest/manual#sec-nix-build>.
+
+- Build a Nix expression:
+
+`nix-build --attr {{expression_name}}`
+
+- Build a sandboxed Nix expression (on non-nixOS):
+
+`nix-build --attr {{expression_name}} --option sandbox true`