Fix issue links to point to eq-usecases instead of ri-usecases.

Just noticed a couple bad links for open and closed issues—they were pointing to the ResponsiveImages/ri-usecases repo instead of ResponsiveImages/eq-usecases.

Sorry if I should’ve made a bug for this; figured since it’s basically just a typo correction it wasn’t worthwhile.

There are also a *lot* of changes in the generated HTML file here. They all look like they are mostly just formatting—I’m assuming I’ve got a newer version of bikeshed than whoever/whenever last updated this. If not or if I’ve got something configured wrong, let me know.