Create castle-ruins.svg

[ghost]

First proposed version of a ruins icon (see issues)

This is my first git-hub action. Hope, I did everything right.

[nebulon42]

Thanks for this PR! Could you please separate each icon into its own PR? This makes it easier to discuss each design separately, since there is not much overlap between the themes.

You would do that by creating a branch from master for each icon and then commit the icon separately to its branch and create a pull request for each icon.

Please also make sure that you save the output of Inkscape as "Plain SVG" as detailed in https://github.com/gmgeo/osmic/blob/master/CONTRIBUTING.md#technical-aspects

Since you mentioned that you are not too familiar with GitHub yet, here are some resources to help you with that:

https://guides.github.com/introduction/flow/
https://gist.github.com/blackfalcon/8428401

On guides.github.com GitHub has other resources that might be of value. The second link assumes that you are using the command line client of Git, which seems a bit difficult first, but really isn't hard to do. If you have any questions, please feel free to ask.