feat(nvim): add nvim-ufo for better fold handling

nvim/lua/config/keymaps.lua

@@ -27,6 +27,9 @@ vim.keymap.set("n", "gy", "`[v`]y", { desc = "Visually select of just pasted con
 -- stylua: ignore
 vim.keymap.set("n", "<leader>wi", ":silent !open -a iA\\ Writer.app '%:p'<CR>", { desc = "Open in iA Writer", noremap = true, silent = true })
 
+vim.keymap.set("n", "-", "<CMD>foldclose<CR>", { desc = "Close code fold" })
+vim.keymap.set("n", "+", "<CMD>foldopen<CR>", { desc = "Open code fold" })
+
 vim.keymap.set("n", "<C-h>", function()
   require("smart-splits").move_cursor_left()
 end)

nvim/lua/plugins/ufo.lua

@@ -0,0 +1,44 @@
+-- Not UFO in the sky, but an ultra fold in Neovim.
+-- https://github.com/kevinhwang91/nvim-ufo
+return {
+  "kevinhwang91/nvim-ufo",
+  dependencies = "kevinhwang91/promise-async",
+  config = function()
+    vim.o.foldcolumn = "1"
+    vim.o.foldlevel = 99
+    vim.o.foldlevelstart = 99
+    vim.o.foldenable = true
+
+    require("ufo").setup({
+      provider_selector = function(bufnr, filetype, bufftype)
+        return { "lsp", "indent" }
+      end,
+    })
+  end,
+  keys = {
+    {
+      "zR",
+      function()
+        require("ufo").openAllFolds()
+      end,
+      desc = "Open all folds",
+    },
+    {
+      "zM",
+      function()
+        require("ufo").closeAllFolds()
+      end,
+      desc = "Close all folds",
+    },
+    {
+      "zK",
+      function()
+        local winid = require("ufo").peekFoldedLinesUnderCursor()
+        if not winid then
+          vim.lsp.buf.hover()
+        end
+      end,
+      desc = "Peek fold",
+    },
+  },
+}