OZ-279: Implementer docs structured as evaluate/adopt/deploy.

[rbuisson]

https://mekomsolutions.atlassian.net/browse/OZ-279

This PR introduces:

• a new nested structure for the implementer section.
• empty placeholder pages
• more content

Miro board: https://miro.com/app/board/uXjVLtlG19g=/?share_link_id=37906699100

@mks-d , this might be bringing too much text actually. It does end up with big blocks of text. But there is a lot to say!

[mks-d]

The evaluate/adopt/deploy journey is an excellent idea 👍

It's important to onboard consumers into our own terminology around Ozone. Namely: an ecosystem of apps. Let's get rid of the notion of component, and let's avoid the long word (application) in favour of the short one (app).

[rbuisson]

Fixes done.
There is some changes to the reader's flow introduced in this PR.
Especially, the Quick Start page.
It's on its own tab now:

But also, it has one single page.
That's pretty ugly but I don't know how to remove that.

Alternatively, we could create 3 pages:

• Online Demo
• Locally
• On Gitpod

I think this will be clearer that the current "Did you check the online demo?" and the 2 tabs for Locally VS Gitpod.

What do you think @mks-d ?