You need a Raspberry Pi (or similar) board to run the code.
You can compile the code by running:
cargo build --target armv7-unknown-linux-gnueabihf --release
The executable will be in the folder target/armv7-unknown-linux-gnueabihf/release/
The code will simply read from channel 0 of the MCP3008 ADC and display the result on stdout.
Please check out Cross compiling Rust for the Raspberry Pi on Linux if you are new to writing Rust code for Raspberry Pi and similar systems.