2b7cb04265 primitives: Add missing re-exports (Tobin C. Harding)
Pull request description:
Add re-exports of types from `taproot` and `merkle_tree`.
ACKs for top commit:
jamillambert:
ACK 2b7cb04265
apoelstra:
ACK 2b7cb04265cdb2d62c1bcc645e19d8bafa132b4b; successfully ran local tests
Tree-SHA512: e837c8e7bfda3e8c5510a15ba19b2b0b433e9e87c961ab9ab81d134288b70bc98364007e8e610e7066732e16f72ea990a782cade9ead6b71ddc9b843753fa0ee