Add clarifying comments based on code review feedback

Co-authored-by: dwinkler1 <22460147+dwinkler1@users.noreply.github.com>

templates/rde/lib/shell-hook.nix

@@ -31,6 +31,7 @@ in ''
   echo "${shellCmds}"
   echo "=========================================================================="
   echo ""
+  # Auto-activate devenv shell if devenv.nix exists (can be disabled in config)
   ${pkgs.lib.optionalString enabledPackages.devenv "${defaultPackageName}-activateDevenv"}
   echo ""
 ''

templates/rde/overlays/r.nix

@@ -13,6 +13,8 @@ final: prev: let
     ++ (with final.extraRPackages; [
       httpgd
     ])
+    # Import custom R packages from project root if file exists
+    # Users can create r-packages.nix in their project to add more packages
     ++ (prev.lib.optional (builtins.pathExists ./r-packages.nix) (import ./r-packages.nix final.rpkgs));
 in {
   quarto = final.rpkgs.quarto.override {extraRPackages = reqPkgs;};

templates/rde/scripts/updateDeps.sh

@@ -3,8 +3,11 @@ set -euo pipefail
 
 echo "🔄 Updating project dependencies..."
 
+# Fetch latest R version from rstats-on-nix
+# This command chain: downloads CSV, extracts last line, gets 4th field (date), removes quotes
 RVER=$( wget -qO- 'https://raw.githubusercontent.com/ropensci/rix/refs/heads/main/inst/extdata/available_df.csv' | tail -n 1 | head -n 1 | cut -d',' -f4 | tr -d '"' ) &&\
 
+# Update rixpkgs date in flake.nix
 sed -i  "s|rixpkgs.url = \"github:rstats-on-nix/nixpkgs/[0-9]\{4\}-[0-9]\{2\}-[0-9]\{2\}\";|rixpkgs.url = \"github:rstats-on-nix/nixpkgs/$RVER\";|" flake.nix
 echo "✅ R date is $RVER"