Improve UX around customizing meta tags per entity bundle (content types, vocabularies, etc)

I found this issue while trying to figure out how to do this. One idea would be just to add this to the README.txt file. I looked in there for the keyword type and when I didn't find it I moved to the queue. Maybe Configuration item 2 in the README.txt could be improved to mention node types?

Nice to see that this functionality is already present. I was previously "hacking" metatags in some preprocess function to do just that, I have to admit that I never paid attention to the "add a meta tag default" link.

As greggles suggest in #6 it may be a good idea to add a note about it in the README.txt. Maybe the link text can be rephrased to be less confusing, but I have no idea about something more clear here. Another option would be to add some little text in the table #prefix to explain how to do it. Or even a line at the end of the table with a link "+ Add an entity type specific metatag default" or something like this.

So there are many possibilities to make this more user friendly but I don't know which solution is better. Ideally this should be so obvious that adding an instruction about it in the readme would not be necessary.

(Specified in readme.txt)

Failed testing, adding new patch.

Just had the same experience as #6. Here's the patch from #8 re-rolled to be relative to metatag module directory.