Example Gallery Improvements

[nabobalis]

Currently the examples written in the examples/ folder could do with major copy editing.

Ideally we would want more introduction text to explain what is going in, probably remove some of the print statements and making sure the rendered html is nice to look at.

Also any places we can plot the returned data using sunpy, we should do so.

[mbobra]

I can work on this. Let me know if there are any more specifics or any particular examples to start with. Otherwise I'll go through one by one and make a series of PRs.