doc: add Debian based setup to readme

README.md

@@ -1,9 +1,9 @@
 # monster
 Monster is a symbolic execution engine for 64-bit RISC-V code
 
-# toolchain setup (mac)
-
-1. Install rust
+# Toolchain setup
+## Install rust
+1. Bootstrap rust
 ```
 $ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
 ```
@@ -12,19 +12,34 @@ $ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
 $ rustup component add rustfmt
 $ rustup component add clippy
 ```
-3. Add cargo to your PATH
+3. Add cargo to your $PATH
 ```
 $ echo 'export PATH="$HOME/.cargo/bin:$PATH"' >> ~/.zshrc && source ~/.zshrc
 ```
 4. Install tool for cross compilation
 ```
 $ cargo install cross
 ```
+
+## Docker and llvm
+### Debian based
+5. Install docker (needed by cross)
+```
+$ apt install docker
+```
+6. Make sure you have a recent version of clang/llvm (>= v9) installed:
+```
+$ apt intall llvm
+```
+
+### Mac
 5. Install docker (needed by cross) with [this installation guide](https://docs.docker.com/docker-for-mac/install/)
 6. Make sure you have a recent version of clang/llvm (>= v9) installed:
 ```
 $ brew install llvm
 ```
+
+## Build and test
 7. Test your toolchain setup by compiling monster:
 ```
 $ cargo build