Add keyboard shortcuts to sloganerator

[jcommelin]

After submitting about 10 slogans, I already wished for keyboard shortcuts. This shouldn't be too hard with JQuery. Something like (Ctrl/Alt)-N for "get new tag" and (Ctrl/Alt)-S for "submit slogan".

But maybe you want to just rely on the Tab-sequence. It is very helpful when you immediately want to grab a new tag. Sometimes I guess I would hit Ctrl-N (or Alt-N) about 5 or 10 times in a row.