moving initialisation to lua, simplify setup

[matu3ba]

@vigoux

1. Currently there is module-template.vim with a intialisation method. A pure lua profile would decrease startup time, so usage should be written into the README of the plugin.

2. Is there a specific reason, why we dont use enable = true as default behavior

require'nvim-treesitter.configs'.setup {
  require'nvim-treesitter.highlight'.setup {
    -- enable = true, REMOVE THIS LINE
    disable = { "c", "cpp", "rust" },
  }
  ...
  require`rainbow`.setup {}

like in the lsp setups? Buffer-specific configurations need to conduct the manual anyway.

3. The lua startup profiler would be more correct or simpler to get correct with this change.

[matu3ba]

@vigoux Kindly ping. Would be nice to have this changed + documented for the 0.5 release.

[vigoux]

Hi, thanks for the reminder.
Though the 0.5 change does not have anything to do here, as this is separate plugin 😉

I'll look into that today hopefully.