feat(blog): add dmn-js@8.3 blog post

[pinussilvestrus]

Very like it, especially the "Encouraging Best Practices... without enforcing them" structure, very cool 👏

[barmac]

LGTM 🚀

[nikku]

Everyone likes it, no one approves :+1:

[nikku]

Added a few minor changes on top, cf. https://github.com/bpmn-io/bpmn.io/commit/04d8e930331efd3c5ecca794e925e489c848ea99.

TLDR:

• call to action! Link to demo!
• not so generic title
• DMN diagram -> DRD (this is what the thing is called)

:clap:

[nikku]

Also updated the example diagram we host on demo.bpmn.io:

It is now TOP_DOWN layouted.

[philippfromme]

@nikku Nice! Thank you! 😄