Merge remote-tracking branch 'upstream/master'

- init.lua: minor edits of section comments for consistency
- init.lua: move diagnostic keymaps together with other keymaps

lua/lazy-bootstrap.lua

@@ -1,4 +1,4 @@
--- [[ Bootstrap lazy plugin manager ]]
+-- [[ Install `lazy.nvim` plugin manager ]]
 --    https://github.com/folke/lazy.nvim
 --    `:help lazy.nvim.txt` for more info
 local lazypath = vim.fn.stdpath 'data' .. '/lazy/lazy.nvim'