Re-order kv commands docs to be more user friendly

[EverlastingBugstopper]

Fixes #553

[gabbifish]

I think the re-ordering of the subcommands is great, but still very, very strongly believe the documentation about --binding/--namespace-id and --env should live at the top of this document; otherwise, this very important information gets buried in subcommands.

[EverlastingBugstopper]

My general thought is that it's confusing to users when you explain high level concepts before they're ready for them - you don't understand bindings and namespace ids when you have yet to create a namespace in the first place. I agree that this might get buried and cmd+f to a single spot might be difficult. Perhaps we should make a heading called "Getting Started" which just has you create a namespace, and then jump into concepts w/ environments and namespace id/binding explanation, followed by the rest of the doc.

[gabbifish]

I like your Getting Started idea! Let's see what Dubs thinks and we can move forward from there :D

[EverlastingBugstopper]

This looks great!