README.md update

[paulloz]

Hello there!

As ink is growing and lots of side projects are being developed, I'm wondering if it wouldn't be the right time to take a minute and update the README.md file.
I think non Unity integrations and other runtimes could be made more visible if mentioned (I'm especially thinking about ink.js on which a pretty huge amount of work have been invested into and which is used quite massively in the community). I'm also thinking about the upcoming VSCode extension which already seems pretty dope and might deserve to be showcased a little.
Maybe a link to the ink-library could be a way to go about this if you don't want to bloat the repo's front page with information.

For posterity, this comment is motivated by a discussion with another Discord user this evening who said they had no idea they could use ink with Godot Engine and found out about it by randomly finding the Discord server and seeing the #godot channel.

Cheers ✌️