question 11 add-dist-tag explanation wording

 Numerous people were running into issues with the instructions for problem 11 - adding a dist tag see workshopper#21 I changed the wording of the instructions to show people how to figure out the package and version of a project.

Fixed typos

problems/11-dist-tag/problem.en.txt

@@ -13,4 +13,8 @@ these distribution tags with the `dist-tag` function.
 
 Run `npm help dist-tag` to learn more about it.
 
+npm dist-add <pkg>@<version> [<tag>] will add a new tag. To find out the name of your current package/version type npm ls. The first line of the output will be the package and version; e.g. user@1.0.1. To add a tag type in the name of the tag.
+
+npm dist-add user@1.0.1 beta
+
 Try adding a dist-tag on your package.