feat: added devenv to templates and removed .envrc entries from .gitignore

.gitignore

@@ -65,3 +65,5 @@ tags
 [._]*.un~
 
 # End of https://www.toptal.com/developers/gitignore/api/direnv,terraform,vim
+
+!templates/**

templates/devenv/.envrc

@@ -0,0 +1,3 @@
+watch_file flake.nix flake.lock
+
+use flake . --no-purel-eval

templates/devenv/flake.nix

@@ -0,0 +1,53 @@
+{
+  inputs = {
+    nixpkgs.url = "github:cachix/devenv-nixpkgs/rolling";
+    devenv.inputs.nixpkgs.follows = "nixpkgs";
+    devenv.url = "github:cachix/devenv";
+
+    flake-utils.url = "github:numtide/flake-utils";
+    treefmt-nix.url = "github:numtide/treefmt-nix";
+  };
+  outputs = {
+    flake-utils,
+    nixpkgs,
+    treefmt-nix,
+    devenv,
+    ...
+  } @ inputs:
+    flake-utils.lib.eachDefaultSystem (
+      system: let
+        pkgs = import nixpkgs {inherit system;};
+
+        treefmtConfig = {...}: {
+          projectRootFile = "flake.nix";
+          programs = {
+            alejandra.enable = true;
+          };
+        };
+
+        treefmtEval = treefmt-nix.lib.evalModule pkgs (treefmtConfig {inherit pkgs;});
+      in {
+        formatter = treefmtEval.config.build.wrapper;
+
+        devShells.default = devenv.lib.mkShell {
+          inherit inputs pkgs;
+
+          modules = [
+            ({pkgs, ...}: {
+              languages = {};
+
+              packages = with pkgs; [];
+
+              processes = {};
+
+              scripts = {};
+
+              services = {};
+
+              tasks = {};
+            })
+          ];
+        };
+      }
+    );
+}

templates/devshell/.envrc

@@ -0,0 +1,3 @@
+watch_file flake.nix flake.lock
+
+use flake