chore(testenv): fix cargo manifest

crates/testenv/Cargo.toml

@@ -2,6 +2,13 @@
 name = "bdk_testenv"
 version = "0.1.0"
 edition = "2021"
+rust-version = "1.63"
+homepage = "https://bitcoindevkit.org"
+repository = "https://github.com/bitcoindevkit/bdk"
+documentation = "https://docs.rs/bdk_testenv"
+description = "Testing framework for BDK chain sources."
+license = "MIT OR Apache-2.0"
+readme = "README.md"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
@@ -14,4 +21,4 @@ anyhow = { version = "1" }
 [features]
 default = ["std"]
 std = ["bdk_chain/std"]
-serde = ["bdk_chain/serde"]
+serde = ["bdk_chain/serde"]