feat: add keymap to swap virtual_text and virtual_lines for diagnostic

plugin/diagswap.lua

@@ -0,0 +1,8 @@
+local state = true
+
+local function swap()
+        vim.diagnostic.config({ virtual_text = not state, virtual_lines = state })
+        state = not state
+end
+
+vim.keymap.set("n", "<leader>dt", swap)