refactor: use nix flake instead venv

flake.nix

@@ -0,0 +1,64 @@
+{
+  description = "Development shell for Personal blog";
+  
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-23.11";
+    flake-utils = {
+      url = "github:numtide/flake-utils";
+    };
+  };
+
+  outputs = { nixpkgs , flake-utils, ... }: flake-utils.lib.eachDefaultSystem (system:
+    let
+      pkgs = import nixpkgs {
+        inherit system;
+      };
+      pelicanplugins-neighbors = ( with pkgs; stdenv.mkDerivation {
+        pname = "pelicanplugins-neighbors";
+        version = "1.2.0";
+        src = pkgs.fetchFromGitHub {
+          owner = "pelican-plugins";
+          repo = "neighbors";
+          rev = "60649ac6f3494d01a37b9c6d3d455f9dc2502d55";
+          hash = "sha256-c6etuRqve9xj6NhGRAim2A0ae8xv6mI/yez+suQuZ8U=";
+        };
+        installPhase = ''
+          cp -r $src/pelican/plugins/neighbors $out
+        '';
+      });
+      pelicanplugins-md_include = ( with pkgs; stdenv.mkDerivation {
+        pname = "pelicanplugins-md_include";
+        version = "1.0.4";
+        src = pkgs.fetchFromGitHub {
+          owner = "pelican-plugins";
+          repo = "markdown-include";
+          rev = "df0b3e55c45471283ca62d6e157b61a8caa35e37";
+          hash = "sha256-y0dIvyEYLbYqkm+6yJOUYI3apzEMJ/N/JUwWTqjdsNg=";
+        };
+        installPhase = ''
+          cp -r $src/pelican/plugins/md_include $out
+        '';
+      });
+  in {
+    devShells = {
+      default = pkgs.mkShell {
+        nativeBuildInputs = with pkgs; [
+          lefthook
+          go-task
+          convco
+          typos
+          shellcheck
+          shfmt
+          python3
+          python3Packages.pelican
+          python3Packages.markdown-include
+        ];
+        shellHook = ''
+          mkdir -p plugins
+          ln -snf "${pelicanplugins-neighbors}" "plugins/neighbors"
+          ln -snf "${pelicanplugins-md_include}" "plugins/md_include"
+        '';
+      };
+    };
+  });
+}