Release 0.15.2

[github-actions]

• #445: Bump node-forge from 1.2.1 to 1.3.0 in /examples/wasm/www
• #446: Bump minimist from 1.2.5 to 1.2.6 in /examples/wasm/www
• #447: Expand crate description and keywords
• #448: Migrate to the Rust 2021 edition
• #449: Add explicit LICENSE file to Wasm demo
• #451: Bump all Wasm demo dependencies to latest versions
• #454: Add configurable LineEnding
• #455: Remove unnecessary impl block
• #456: Use an explicit type when converting into Options
• #457: Remove old macro, move logic to WordSeparator::new
• #458: Test with Rust 1.56 in CI
• #459: Fix the display of OptimalFit in interactive demo
• #461: Update to terminal_size 0.2.
• #462: Implement small recommendations from Clippy
• #464: Bump all npm dependencies for Wasm example
• #465: Use by_ref to iterate over captured variables
• #467: Fix unfill and refill crashes
• #468: Fix refill to add back correct line ending
• #469: Apply small Clippy suggestions
• #470: Release 0.15.1
• #471: Cross-link break_words with word_splitter
• #473: Update binary sizes
• #474: Bump all dependencies
• #475: Remove redundant if: braces
• #476: Move benchmarks to their own project
• #477: Cache nested target/ folders
• #478: Add fast paths to fill and wrap
• #479: Fix small Clippy warning
• #480: Mark Options as non_exhaustive
• #481: Bump termion demo dependency to 2.0.1
• #482: Release 0.16.0
• #483: Also derive Eq for Penalties