Add Rust formatting config and README (#6)

README.md

@@ -4,5 +4,14 @@ Implements
 [BIP-322](https://github.com/bitcoin/bips/blob/master/bip-0322.mediawiki),
 generic message signing and verification.
 
+
+## Types of Signatures 
+
+- simple (only witness stack, consensus encoded, base64)
+- full (base64 encoded `to_sign`)
+- proof-of-funds (add utxos to `to_sign`)
+- No need to implement legacy  
+
 ## Test Vectors
+
 https://github.com/bitcoin/bitcoin/blob/29b28d07fa958b89e1c7916fda5d8654474cf495/src/test/util_tests.cpp#L2747

rustfmt.toml

@@ -0,0 +1,6 @@
+edition = "2021"
+max_width = 100
+newline_style = "Unix"
+tab_spaces = 2
+use_field_init_shorthand = true
+use_try_shorthand = true