feat: add option to disable underline(#33)

Author: haorenW1025

lua/diagnostic.lua

@@ -77,7 +77,9 @@ function M.publish_diagnostics(bufnr)
   vim.lsp.util.buf_clear_diagnostics(bufnr)
   vim.lsp.util.buf_diagnostics_save_positions(bufnr, result.diagnostics)
   util.buf_diagnostics_save_positions(bufnr, result.diagnostics)
-  vim.lsp.util.buf_diagnostics_underline(bufnr, result.diagnostics)
+  if vim.api.nvim_get_var('diagnostic_enable_underline') == 1 then
+    vim.lsp.util.buf_diagnostics_underline(bufnr, result.diagnostics)
+  end
   if vim.api.nvim_get_var('diagnostic_show_sign') == 1 then
     util.buf_diagnostics_signs(bufnr, result.diagnostics)
   end

plugin/diagnostic.vim

@@ -33,6 +33,10 @@ if ! exists('g:diagnostic_show_sign')
     let g:diagnostic_show_sign = 1
 endif
 
+if ! exists('g:diagnostic_enable_underline')
+    let g:diagnostic_enable_underline = 1
+endif
+
 if ! exists('g:diagnostic_sign_priority')
     let g:diagnostic_sign_priority = 20
 endif