Rewrite maifetch in Rust

[Errordog2]

Fixes #1.

Rewrites the project from Go to Rust while keeping the CLI behavior and MaiTea output flow aligned with the original tool:

• replaces the Go module with a Rust binary crate
• preserves JSON config loading with the same maifetch.json shape
• supports the existing CLI options for access token, config file, score count, and logo size
• supports both MAIFETCH_* env vars from the original Go envconfig prefix and the documented MAITEA_* env vars
• keeps the MaiTea API client methods for profiles, tracks, plays, scores, pagination, and status
• renders the same profile summary fields and recent score layout, with optional image-to-ASCII logo output
• updates build docs to use cargo build --release

Validation performed:

• cargo fmt --check
• cargo metadata --no-deps --format-version 1

I also attempted cargo check, but this Windows environment does not have a system linker installed: the MSVC target is missing link.exe / Windows SDK libs, and the GNU target is missing gcc.exe. The Rust toolchain and dependencies were otherwise installed and resolved successfully.