add vendored-openssl feature to allow embed openssl statically

Author: ndusart

Cargo.lock

@@ -5,6 +5,9 @@ edition = "2021"
 authors = ["Nicolas Dusart <[email protected]>", "Freedelity"]
 license = "MIT"
 
+[features]
+vendored-openssl = ["ssh2/vendored-openssl"]
+
 [dependencies]
 anyhow = "1.0"
 clap = { version = "4.4", default-features = false, features = ["derive", "std", "help", "usage"] }

Cargo.toml

@@ -64,6 +64,12 @@ You can simply build this with the **Rust** toolchain (using **cargo** package m
 cargo build --release
 ```
 
+This build will be linked against the OpenSSL library of your system. If this makes an issue to deploy it on a machine with an incompatible version of OpenSSL, you can statically link OpenSSL in your binary by enabling the `vendored-openssl` feature (this will add ~4MB to the final binary):
+
+```sh
+cargo build --release --feature vendored-openssl
+```
+
 ## License
 
 This project is licensed under the [MIT license].