Echo JS 0.11.0

Agreed.  This just feels like bringing in a library to do something JavaScript already does.

My first instinct was that this would be a rough equvalent to a `Money` or `Decimal` data type/conversion to/from string for use with Larger or arbitrary values stored as a Uint8Array or similar for serialization/deserialization.  Or even BigInt with N positions reserved for "decimal" offset or something.