Added Rust examples and explanations
As I've began learning the Rust programming language I've decided to start writing these challenges in Rust as well a Python.
Rust is a system's programming language, and so it is interesting to see the difference in code size, and performance between the two languages. Both solutions were almost identical in function size - maybe less so in readability - but the Rust code did require more set up to fetch user input, cast it, and then benchmark the factorial finder functions. In terms of performance, Rust wins by a significant margin, in some cases - at least for calculating relatively small factorials - the benchmark results were 0 microseconds.
The Rust explanation can be found in the Rust/ directory and the code can be found in Rust/src/main.rs.
Full Changelog: v1.0.0...v1.1.0