Make developer docs / API more prominent

[pavlenex]

Our new API is currently quite hidden as mentioned here.

We should discuss on how to display the link to the API more prominently on the website.

[dennisreimann]

We could add a fifth point "Automation via the API" with an introduction text like I mentioned here to the selling points section.

Other than that I think one would expect to find it more prominently in the docs than on the website. For that I still see a use case for the "Explore by topic" section, which we discussed here.

[pavlenex]

@dennisreimann That sounds good to me. Also I'd add Developers in the menu with API sub-menu, and later on docs and plugins for devs. If you're tackling the copy on the site, please try to make it simple to understand and easy to translate.

[pavlenex]

Awaiting for the icons from @dstrukt to proceed.