use('nvim-telescope/telescope.nvim')
use('crispgm/telescope-heading.nvim')

require('telescope').load_extension('heading')

-- add nvim-treesitter
use('nvim-treesitter/nvim-treesitter')
-- make sure you have already installed treesitter modules
require('nvim-treesitter.configs').setup({
    ensure_installed = {
        -- ..
        'markdown',
        'rst',
        -- ..
    },
})
-- enable treesitter parsing
local telescope = require('telescope')
telescope.setup({
    -- ...
    extensions = {
        heading = {
            treesitter = true,
        },
    },
})
-- `load_extension` must be after `telescope.setup`
telescope.load_extension('heading')

local telescope = require('telescope')
telescope.setup({
    -- ...
    extensions = {
        heading = {
          picker_opts = {
              layout_config = { width = 0.8, preview_width = 0.5 },
              layout_strategy = 'horizontal',
          },
        },
        -- ...
    },
})