Linux install docs

[palmtree5]

Before PR

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• [x] Added frontmatter header to your doc based on this guide
• [x] Formatted the doc to fit jekyll requirements based on this guide
• [x] Added link to a sidebar based on this guide

Doc info

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• Category: guides
• Subject: Installation guides for various Linux distros (see also #78 )
• Author: @Kowlin and myself

There are currently three categories available: troubleshooting, guides and custom cog documentation, please specify one of those in the list above Subject might be anything, but we recommend sticking to 3-4 words

[Kowlin]

leaving this for @Twentysix26 due the fact that its a big change from what we currently have here. And many thanks for doing the work on this palm ;)

[Chovin]

few comments:

• [x] submenu/page of the collection of linux distros so that the sidebar is just Windows/Mac/Linux
• [x] fix main page dead link

[palmtree5]

Fixed the dead main page link with a new page called red_install_linux that just lists links to all the guides. I tried creating a category for all the linux guides but clicking it doesn't do anything other than redirect back to the main page

[palmtree5]

Ok, category for all linux guides isn't happening. It'll just be a page linked in the sidebar and on the main page with all the guides listed there

[palmtree5]

Added docs for OpenSUSE