docs(v3.5.0): update README for integrated mg_dotfiles and security improvements

- Integrated mg_dotfiles as regular directory (not submodule)
- Added .zshrc.local.example template for local configs without secrets
- Added mg_dotfiles/zsh/.zshrc.local to .gitignore to protect API keys
- Updated README to reflect mg_dotfiles integration and new structure
- Added nvim configuration directory with LazyVim setup

mg_dotfiles/nvim/lua/plugins/fff.lua

@@ -0,0 +1,31 @@
+return {
+  "dmtrKovalenko/fff.nvim",
+  build = function()
+    -- this will download prebuild binary or try to use existing rustup toolchain to build from source
+    -- (if you are using lazy you can use gb for rebuilding a plugin if needed)
+    require("fff.download").download_or_build_binary()
+  end,
+  -- if you are using nixos
+  -- build = "nix run .#release",
+  opts = { -- (optional)
+    debug = {
+      enabled = true, -- we expect your collaboration at least during the beta
+      show_scores = true, -- to help us optimize the scoring system, feel free to share your scores!
+    },
+    preview = {
+      line_numbers = true,
+    },
+  },
+  -- No need to lazy-load with lazy.nvim.
+  -- This plugin initializes itself lazily.
+  lazy = false,
+  keys = {
+    {
+      "ff", -- try it if you didn't it is a banger keybinding for a picker
+      function()
+        require("fff").find_files()
+      end,
+      desc = "FFFind files",
+    },
+  },
+}