Update readme and add compression info

README.md

@@ -14,14 +14,25 @@ subscribe to events, and work with the low-level RPC primitives.
 To ease developpemnt we use [cross-rs](https://github.com/cross-rs/cross), 
 but you can install all toolchain component or your local computer and replace cross with cargo.
 
-By default the option "-Zfmt-debug=none" is set meaning all debug print (:?) are off. If you can disable this option at any time.
+By default the option "-Zfmt-debug=none" is set meaning all debug print (:?) are off. You can disable this option at any time in `.cargo/config.toml`.
 
 There are more size optimisation done you can check the `.cargo/config.toml`, `Cargo.toml`, `Cross.toml` and [min-sized-rust](https://github.com/johnthagen/min-sized-rust) for more info.
 
-# Compilation
+## Compilation
 
 Simply do `cross clippy --all-targets` to compile everything
 
+For faster transfer you can simply compress binary and decompress it inside the vm
+
+## Compression
+
+You can compress and decompress your files with those commands for faster transfer and/or disk usage.
+
+```bash
+xz -9e --riscv --lzma2=dict=512KiB,lc=3,lp=0,pb=2 -c binary > binary.xz
+xz -d binary.xz
+```
+
 ## Examples
 
 Each crates has some examples of how to use it crate are in the `examples` directory.