Fix nvim lsp (#98)

* Fix Neovim LSP Configuration

Recently, nvim had breaking changes for adding LSP configurations.
See also
https://www.reddit.com/r/neovim/comments/r8p0ye/lspconfig_ensure_this_server_is_listed_in_server/

* Clean up Neovim LSP Configuration

Have it work out of the box.

Author: bramhooimeijer

README.md

@@ -87,28 +87,24 @@ this to your [coc.nvim configuration file][vim_coc_nvim_config_file]:
 This requires [`nvim-lspconfig`](https://github.com/neovim/nvim-lspconfig).
 ```lua
 lua << EOF
-local lspconfig = require'lspconfig'
 -- Only define once
-if not lspconfig.hdl_checker then
-  require'lspconfig/configs'.hdl_checker = {
+if not require'lspconfig.configs'.hdl_checker then
+  require'lspconfig.configs'.hdl_checker = {
     default_config = {
     cmd = {"hdl_checker", "--lsp", };
     filetypes = {"vhdl", "verilog", "systemverilog"};
       root_dir = function(fname)
-        -- will look for a parent directory with a .git directory. If none, just
-        -- use the current directory
-        return lspconfig.util.find_git_ancestor(fname) or lspconfig.util.path.dirname(fname)
-        -- or (not both)
-        -- Will look for the .hdl_checker.config file in a parent directory. If
-        -- none, will use the current directory
-        return lspconfig.util.root_pattern('.hdl_checker.config')(fname) or lspconfig.util.path.dirname(fname)
+        -- will look for the .hdl_checker.config file in parent directory, a
+        -- .git directory, or else use the current directory, in that order.
+        local util = require'lspconfig'.util
+        return util.root_pattern('.hdl_checker.config')(fname) or util.find_git_ancestor(fname) or util.path.dirname(fname)
       end;
       settings = {};
     };
   }
 end
 
-lspconfig.hdl_checker.setup()
+require'lspconfig'.hdl_checker.setup{}
 
 EOF
 ```