If you have Rust installed, you can simply run:
$ cargo build --release
to build an executable. You can then run the executable found in target/release/wows_armor to run the calculations (note: see below about running with "info").
The first time you run the executable, it will download all of the metadata, cache HTTP requests in the cache/ directory, and then cache all of the ship metadata in the ships.dat file. If you edit any of the ship data structs in the source code you will need to delete and recreate the ships.dat file.
For debugging, you can change the logging level using:
$ RUST_LOG=wows_armor=trace cargo run
Valid levels include trace, debug, info, warn, and error. The default is warn.
Note that when running out of the box, all of the calculated results are computed at the info level, so you should run using:
$ RUST_LOG=wows_armor=info ./target/release/wows_armor
to see the full output.