Keep assets/iris updated

[mmalmi]

The current version of Iris served by rod is 6 months old. Would be cool to add a script that keeps it updated.

https://github.com/mmalmi/rod/tree/master/assets/iris

[esomore]

What is the command on https://github.com/irislib/iris-lib to produce the contents of assets/?

[mmalmi]

That's actually yarn build @ https://github.com/irislib/iris-messenger