Improved quick-start documentation

- Added information about how to fix an error encountered
 with the default install

- Added information about missing rtmpsink plugin

The line block is used to prevent the paths mentioned
from being split by newlines (to improve readability).
However, this seems to cause a line space between
the first and second sub-bullet.
Remove the `|`s so it looks like

```
* If you encounter the error ``"ImportError: DLL load failed"`` when
  attempting to run freeseer, copy the contents of
  ``<GStreamer_dir>\<version_num>\sdk\bindings\python\v2.7\lib`` to
  ``<GStreamer_dir>\<version_num>\lib``, and delete
  ``<GStreamer_dir>\<version_num>\lib\gstreamer-0.10\libgstpython-v2.6.dll``
* Other stuff goes here
```