Add Factorio topic

[sparr]

Please confirm this pull request meets the following requirements:

• I followed the contributing guidelines: https://github.com/github/explore/blob/main/CONTRIBUTING.md.
• I am not the sole author or employee of a company who created either the topic I am modifying/adding or the collection entry I am modifying/adding.

Which change are you proposing?

• Suggesting edits to an existing topic or collection
• Curating a new topic or collection
• Something that does not neatly fit into the binary options above

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Curating a new topic or collection

• I've formatted my changes as a new folder directory, named for the topic or collection as it appears in the URL on GitHub (e.g. https://github.com/topics/[NAME] or https://github.com/collections/[NAME])
• My folder contains a *.png image (if applicable) and index.md
• All required fields in my index.md conform to the Style Guide and API docs: https://github.com/github/explore/tree/main/docs

About 850 repos use this topic. I added it to my own repos for mods for the game today, and noticed it had no topic page, so I decided to add one. The topic page will help explain the context of a mod or tool or scenario for someone visiting a related repo who hasn't heard of the game.

Per https://factorio.com/support/press-kit I have included the factorio logo image.

Press info

We are happy that you are interested in featuring the game on your channel / site. This page should help give you some details, information, and assets, that help you make the best content possible. Let us know if there is anything we can help you with.

You are welcome to use any of the assets, screenshots, and artwork, that you can find on our website.

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We have prepared a single archive for download containing our logos, screenshots, and artwork you may use for press purposes. You can download the Press Kit here.

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Please note: we will close your PR without comment if you do not check the boxes above and provide ALL requested information.

[tomthorogood]

the topics must grow