New "use-cases" tag to replace DAO Use Cases forum category

housekeeping

#1

Based on some feedback and in the interest of keeping the number of categories at a manageable level I have moved all threads that were in the DAO Use Cases category to the Product category and added a “use-cases” tag that we can use to coordinate around use case discussions going forward. If use-case discussions end up overwhelming the product-development focused discussions in the Product category then we can either make use-cases its own sub-category or break it out into its own top-level category again. Thanks all who gave feedback and started interesting discussions about DAO use cases! Rock on!