make diagnostics prettier and show them in pop-up

basic/nvim/plugconf/lspconfig.lua

@@ -14,3 +14,27 @@ vim.api.nvim_create_autocmd('LspAttach', {
     vim.keymap.set('n', '<leader>p', vim.diagnostic.goto_prev, opts)
   end,
 })
+
+-- Show diagnostics in bordered pop-up
+vim.diagnostic.config { virtual_text = false, float = { border = 'rounded' } }
+vim.lsp.handlers['textDocument/hover'] = vim.lsp.with(
+  vim.lsp.handlers.hover, { border = 'rounded' }
+)
+vim.lsp.handlers['textDocument/signatureHelp'] = vim.lsp.with(
+  vim.lsp.handlers.signature_help, { border = 'rounded' }
+)
+vim.o.updatetime = 500
+vim.api.nvim_create_autocmd({'CursorHold'}, {
+  pattern = {'*'},
+  callback = function(ev)
+    vim.diagnostic.open_float(nil, { focus = false })
+  end,
+})
+
+-- Set diagnostic signs
+local signs = { Error = ' ', Warning = ' ', Hint = ' ', Information = ' ' }
+for type, icon in pairs(signs) do
+  local hl = 'DiagnosticSign' .. type
+  vim.fn.sign_define(hl, { text = icon, texthl = hl, numhl = "" })
+end
+