docs: update readme to use nvim-lspconfig (#8)

Author: asharkhan3101

README.md

@@ -8,25 +8,11 @@ A Language Server for **proto3** files. It uses tree-sitter parser for all opera
 - [x] Go to definition
 - [x] Diagnostics
 
-## Installation and testing
+## Installation
 
-Run `cargo install protols` to install and add below to your `init.lua` until we start shipping this via Mason.
+Run `cargo install protols` to install and add below to setup using [`nvim-lspconfig`](https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md#protols) until we start shipping this via Mason.
 
 ```lua
-local client = vim.lsp.start_client({
-	name = "protols",
-	cmd = { vim.fn.expand("$HOME/.cargo/bin/protols") },
-})
-
-if not client then
-	vim.notify("Could not connect to protols server")
-end
-
-vim.api.nvim_create_autocmd("FileType", {
-	pattern = "proto",
-	callback = function()
-		vim.lsp.buf_attach_client(0, client)
-	end,
-})
+require'lspconfig'.protols.setup{}
 
 ```