chore: move code around

- deprecate config.lua file
- move icon config code into renderer/icons
- move file opening config in open-file.lua

lua/nvim-tree/renderer/icons.lua

@@ -0,0 +1,61 @@
+local M = {}
+
+function M.get_config()
+  local show_icons = vim.g.nvim_tree_show_icons or { git = 1, folders = 1, files = 1, folder_arrows = 1 }
+  local icons = {
+    default = "",
+    symlink = "",
+    git_icons = {
+      unstaged = "✗",
+      staged = "✓",
+      unmerged = "",
+      renamed = "➜",
+      untracked = "★",
+      deleted = "",
+      ignored = "◌"
+    },
+    folder_icons = {
+      arrow_closed = "",
+      arrow_open = "",
+      default = "",
+      open = "",
+      empty = "",
+      empty_open = "",
+      symlink = "",
+      symlink_open = "",
+    },
+  }
+
+  local user_icons = vim.g.nvim_tree_icons
+  if user_icons then
+    if user_icons.default then
+      icons.default = user_icons.default
+      icons.symlink = user_icons.default
+    end
+    if user_icons.symlink then
+      icons.symlink = user_icons.symlink
+    end
+    for key, val in pairs(user_icons.git or {}) do
+      if icons.git_icons[key] then
+        icons.git_icons[key] = val
+      end
+    end
+    for key, val in pairs(user_icons.folder or {}) do
+      if icons.folder_icons[key] then
+        icons.folder_icons[key] = val
+      end
+    end
+  end
+
+  local has_devicons = pcall(require, 'nvim-web-devicons')
+  return {
+    show_file_icon = show_icons.files == 1,
+    show_folder_icon = show_icons.folders == 1,
+    show_git_icon = show_icons.git == 1,
+    show_folder_arrows = show_icons.folder_arrows == 1,
+    has_devicons = has_devicons,
+    icons = icons
+  }
+end
+
+return M