chore: rename lib folder to nvim-tree

Allows external access to the lua api and follow neovim plugins better
practices

lua/nvim-tree/utils.lua

@@ -0,0 +1,14 @@
+local M = {}
+local api = vim.api
+
+function M.path_to_matching_str(path)
+  return path:gsub('(%-)', '(%%-)'):gsub('(%.)', '(%%.)'):gsub('(%_)', '(%%_)')
+end
+
+function M.echo_warning(msg)
+  api.nvim_command('echohl WarningMsg')
+  api.nvim_command("echom '[NvimTree] "..msg:gsub("'", "''").."'")
+  api.nvim_command('echohl None')
+end
+
+return M