nodePackages: reformat generate.sh

The shell script felt somewhat crammed, with commands and comments on
every line. Grouping commands and comments and giving them some space
feels like an improvement to me.

pkgs/development/node-packages/generate.sh

@@ -1,9 +1,20 @@
 #!/usr/bin/env bash
+
 set -eu -o pipefail
+
 cd "$( dirname "${BASH_SOURCE[0]}" )"
+
 node2nix=$(nix-build ../../.. -A nodePackages.node2nix)
+
 rm -f ./node-env.nix
-${node2nix}/bin/node2nix -i node-packages.json -o node-packages.nix -c composition.nix --pkg-name nodejs-14_x
+
+# Track the latest active nodejs LTS here: https://nodejs.org/en/about/releases/
+${node2nix}/bin/node2nix \
+    -i node-packages.json \
+    -o node-packages.nix \
+    -c composition.nix \
+    --pkg-name nodejs-14_x
+
 # using --no-out-link in nix-build argument would cause the
 # gc to run before the script finishes
 # which would cause a failure