Provenance
==========
The owner of an inscription can create child inscriptions, trustlessly
establishing the provenance of those children on-chain as having been created
by the owner of the parent inscription. This can be used for collections, with
the children of a parent inscription being members of the same collection.
Children can themselves have children, allowing for complex hierarchies. For
example, an artist might create an inscription representing themselves, with
sub inscriptions representing collections that they create, with the children
of those sub inscriptions being items in those collections.
### Specification
To create a child inscription C with parent inscription P:
- Create an inscribe transaction T as usual for C.
- Spend the parent P in one of the inputs of T.
- Include tag `3`, i.e. `OP_PUSH 3`, in C, with the value of the serialized
binary inscription ID of P, serialized as the 32-byte `TXID`, followed by the
four-byte little-endian `INDEX`, with trailing zeroes omitted.
_NB_ The bytes of a bitcoin transaction ID are reversed in their text