added adr with user docs navigation proposal

[enekofb]

just draft to have further discussions

[lasomethingsomething]

IMO the proposed categories are quite broad as to be almost meaningless. If I saw "Operations" I would not know to expect what looks like observability. And sections like "guides/tutorials" end up becoming catch-all buckets where people stash things when they don't know where else to put them (this already happened and I emptied out almost all of the "Guides" section to make the content discoverable).

I'd propose the following, at minimum (users do NOT want to spend a lot of time digging for information):

• Getting Started
• Application Development (content for the app dev persona); underneath can be another level/drop-down with the topics listed
• Platform Engineering (content for the platform eng persona); ""
• Observability (in place of the proposed "Operations" category)
• Tutorials (restricted only to content that is actually how-to--the user guide in itself is a how-to but a tutorial is more specific than that)