Fix RST code-block rendering for (read) examples and add more complex example of (read) usage

Without the blank line after `.. code-block:: hy`, the entire block is ignored instead of rendered.

While I was in there, I added a more complex example of `(read)` usage from a file, highlighting one way `EOFError` can be used.

Of course, I'm happy to amend and improve/iterate, even if it turns out nobody but me likes such a verbose example and it needs to just be purged and trim this PR down to just that first commit (since the first commit is definitely a lot less controversial, being that it's a RST syntax fix and some very minor whitespace changes).