fix: allow for lazy loading telescope with notify

[brphilly]

Some users may only load telescope when require("telescope") is first executed (using packer's module key), so avoid doing this in notify setup otherwise loading notify will also load telescope.

Also recommend :Telescope notify notify rather than :Telescope notify since the former will work even if telescope is loaded after notify and require("telescope").load_extension("notify") hasn't been run.

Edit: Forgot to mention that g:loaded_telescope is defined here
https://github.com/nvim-telescope/telescope.nvim/blob/3f45d64e9c47ad9eef273ddab65790a84cced30b/plugin/telescope.vim#L6-L9

[rcarriga]

Hey thanks for the PR! 😄

I'm not a fan of the Telescope notify notify, it's not as easy to use and shouldn't be the recommended way to compensate for a niche quirk. Instead let's add a note below to say something about calling require("telescope").load_extension("notify") manually if telescope is lazy loaded

[brphilly]

Ok I've made the requested changes. Let me know what you think.

[rcarriga]

Perfect! Thanks again 😁