Updated Home (markdown)

Home.md

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 This is the wiki for the [MicroPython](http://micropython.org/) project, which puts an implementation of Python 3.x on a microcontroller or embedded system.
 
 This wiki complements the [official documentation](https://docs.micropython.org/) and aims to provide a place for community-edited documentation, tips, tricks, and guides. Anyone with a GitHub account can contribute.
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+This wiki replaces the former [Gollum Wiki](https://wiki.micropython.org/gollum/Home) on micropython.org and the content from there is being migrated over. In the meantime, you can access it [here](https://wiki.micropython.org/gollum/Home).