strange library config.. unable to mod (for now)

[AceOfSmaydes]

Today I redownloaded factorio ( I was addicted my last semester needed to stop before I failed my semester) and attempted to mod the game how I remembered from a previous tutorial. Except when I went into the folders to create a mod folder the factorio library was very very different. Is this a patch and if so how can I mod the game through downloading mods and inserting them into the game files.
BTW I have the steam version.

[Loewchen]

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