add render-markdown to cmp

Former-commit-id: 7c54507f0f

home/programs/nvim/plugins/cmp.nix

@@ -21,6 +21,7 @@
           }
           { name = "nvim_lua"; }
           { name = "mkdnflow"; }
+          { name = "render-markdown"; }
           { name = "path"; }
         ];