add example dynamic definitions to read me

[WietseWind]

Thanks @shortthefomo - but the added link (see "Files changed") is pointing to a transaction, not the example with custom definitions, right? I think you may have wanted to link to the Samples folder?

[shortthefomo]

darn copy past clipboard caught me out there, fixed link :O

[WietseWind]

I think this one is more suitable?

https://github.com/WietseWind/xrpl-accountlib/blob/master/samples/sign-custom-defs.js

It's in the actual repository samples folder :) https://github.com/WietseWind/xrpl-accountlib/tree/master/samples

[WietseWind]

Thank you 🤗