Merge 'upstream' refactor treesitter, which-key, uv/loop, update README

*  Ihsan Tonuzi refactor: update treesitter and which-key config
*  Michael L. Check for loop or uv for lazypath
*  Matt Gallagher Add note in README about lazy-lock.json
*  theoboldalex Update README.md

lua/lazy-bootstrap.lua

@@ -1,7 +1,7 @@
 -- [[ Install `lazy.nvim` plugin manager ]]
 --    See `:help lazy.nvim.txt` or https://github.com/folke/lazy.nvim for more info
 local lazypath = vim.fn.stdpath 'data' .. '/lazy/lazy.nvim'
-if not vim.uv.fs_stat(lazypath) then
+if not (vim.uv or vim.loop).fs_stat(lazypath) then
   local lazyrepo = 'https://github.com/folke/lazy.nvim.git'
   local out = vim.fn.system { 'git', 'clone', '--filter=blob:none', '--branch=stable', lazyrepo, lazypath }
   if vim.v.shell_error ~= 0 then