wrapping: add plugin for soft word wrapping

lua/plugins/wrapping.lua

@@ -0,0 +1,9 @@
+return {
+  "andrewferrier/wrapping.nvim",
+  config = function()
+    require("wrapping").setup {
+      softener = { markdown = 1.3 },
+    }
+    require("wrapping").set_mode_heuristically()
+  end,
+}