Add GitHub shape/icon library to draw.io

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• I have searched the issue tracker for a feature request that matches the one I want to file, without success.

Describe the solution you'd like I would love the GitHub icon and shape library to be a part of the draw.io default libraries. The shapes are publicly visible via https://primer.style/octicons/ and can be used under an MIT license (see https://github.com/primer/octicons). Thanks