nested list items

[justinmk]

(Continuation of #12 )

Problem

#16 added parsing for list items as (line_li), but these don't "nest".

Example of a nested list

api.txt has many nested lists.

https://github.com/neovim/neovim/blob/52e4b779e3df1335efc4774e8dfc199d07e24bfd/runtime/doc/api.txt#L3257-L3273

   • callback (function|string) optional: if a string, the name
     of a Vimscript function to call when this autocommand is
     triggered. Otherwise, a Lua function which is called when
     this autocommand is triggered. Cannot be used with
     {command}. Lua callbacks can return true to delete the
     autocommand; in addition, they accept a single table
     argument with the following keys:
     • id: (number) the autocommand id
     • event: (string) the name of the event that triggered the
       autocommand |autocmd-events|
     • group: (number|nil) the autocommand group id, if it
       exists
     • match: (string) the expanded value of |<amatch>|
     • buf: (number) the expanded value of |<abuf>|
     • file: (string) the expanded value of |<afile>|
     • data: (any) arbitrary data passed to
       |nvim_exec_autocmds()|