I know, I know, “documentation” doesn’t exactly scream headline feature. But hear me out: making Home Assistant more approachable is one of our biggest missions this year, and darn good documentation is a big part of that. We’ve expanded our documentation team and are investing heavily in this, and the new templating docs are the very first taste of what’s to come. I’m really proud of where this is heading. 
I assume I'm in the minority on this, but I think reading every manual and document from software to even appliances is a really nice "life-hack" with the amounts of things you will realize your software and hardware can do. Specially in the Smart (or not so much) Home, where appliances hide option like turning the beeps off under odd key combinations.
It's honestly frustrating useful features and choices are hidden beneath obtuse language or hundreds of redundant pages.
So I'm incredibly happy to hear of investment on documentation!
I've done many templates, and before this release I've already noticed the improved documentation and it is probably going to save me so much more time than a lot of (of course necessary) software improvements in homeassistant might have in its place.
Navigating the Jinja original page... (no offense to the jinja developers, writing and hosting documentation well isn't easy) was a headache. It doesn't support dark mode nicely with any browser extension or css trick, the index does not follow you so you have to constantly hit the Home key... it was incredibly tedious.
Now? It's all in HA's documentation, which is on a fluid, intuitive webpage with incredible examples. And now the autocomplete "intellisense" like feature is the cherry on top.
Incredible stuff, I hope to see more love given to integration documentation, specially for those integrations that have been in HA for a while, and had more and more headings added to it. It really increases HA's value.
It reminds me of Archlinux, some pick said Linux distribution because of its incredible wiki, and many including myself use it even if they use other distributions because of how good it is!