Telescope integration

[teocns]

Follows https://github.com/nvim-telescope/telescope.nvim/blob/master/developers.md

beware I haven't had the chance to test thoroughly, it is a freshly baked implementation

[ptdewey]

Thanks for the PR! Telescope integration is something I'd be happy to merge in when its ready.

I just tested this, and it is erroring out when selecting an entry from the telescope menu:

E5108: Error executing lua: ...rojects/testing/yankbank-nvim/lua/yankbank/telescope.lua:35: attempt to call field 'tbl_index' (a nil value)
stack traceback:
        ...rojects/testing/yankbank-nvim/lua/yankbank/telescope.lua:35: in function 'run_replace_or_original'
        ...re/nvim/lazy/telescope.nvim/lua/telescope/actions/mt.lua:65: in function 'key_func'
        ...hare/nvim/lazy/telescope.nvim/lua/telescope/mappings.lua:253: in function <...hare/nvim/lazy/telescope.nvim/lua/telescope/mappings.lua:252>

Taking a look at line 35, it appears that vim.tbl_index is not a valid function, but it should be pretty simple to modify the code to get the entry index (a loop would suffice as the table is quite small).

Transitioning to some minor feedback, I think it would be nice if it used the telescope split previewer when the editor window is sufficiently large, and I would like the newline display character to be set with an option as I don't personally like using glyph characters (but I'm fine with it being the default option).

Please reach out if you have any questions, and thanks again for the contributions.