BIP360: Pay to Merkle Root (P2MR) (#1670)

Review comments and assistance by:
  Armin Sabouri <armins88@gmail.com>
  D++ <82842780+dplusplus1024@users.noreply.github.com>
  Jameson Lopp <jameson.lopp@gmail.com>
  jbride <jbride2001@yahoo.com>
  Joey Yandle <xoloki@gmail.com>
  Jon Atack <jon@atack.com>
  Jonas Nick <jonasd.nick@gmail.com>
  Kyle Crews <kylecrews@Kyles-Mac-Studio.local>
  Mark "Murch" Erhardt <murch@murch.one>
  notmike-5 <notmike-5@users.noreply.github.com>
  Vojtěch Strnad <43024885+vostrnad@users.noreply.github.com>

Co-authored-by: Ethan Heilman <ethan.r.heilman@gmail.com>
Co-authored-by: Isabel Foxen Duke <110147802+Isabelfoxenduke@users.noreply.github.com>

bip-0360/ref-impl/rust/README.md

@@ -0,0 +1,45 @@
+
+# p2mr test vectors
+
+This rust project contains the test vectors for BIP-360
+
+
+## Run Test Vectors
+
+These test vectors are being developed in conjunction with forks of [rust-bitcoin](https://github.com/jbride/rust-bitcoin/tree/p2mr) and [rust-miniscript](https://github.com/jbride/rust-miniscript/tree/p2mr-pqc) customized with p2mr functionality.
+
+
+1. environment variables
+   ```
+   // Specify Bitcoin network used when generating bip350 (bech32m) address
+   // Options: regtest, testnet, signet
+   // Default: mainnet
+   $ export BITCOIN_NETWORK=<regtest | testnet | signet >
+   ```
+
+1. run a specific test:
+   ```
+   $ cargo test test_p2mr_single_leaf_script_tree -- --nocapture
+   ```
+
+## Local Development
+
+
+All P2MR/PQC enabled bitcoin crates are temporarily available in a custom crate registry at:  `https://crates.denver.space`.
+These crates will be made available in `crates.io` in the near future.
+
+Subsequently, you will need to execute the following at the root of your rust workspace:
+
+```bash
+mkdir .cargo \
+    && echo '[registries.kellnr-denver-space]
+index = "sparse+https://crates.denver.space/api/v1/crates/"' > .cargo/config
+```
+
+Afterwards, for all P2MR/PQC enabled dependencies used in your project, include a "registry" similar to the following:
+
+```bash
+bitcoin = { version="0.32.6", registry = "kellnr-denver-space" }
+```
+
+