Icon request: half-star

Icon name: half-star
Use case: For example, for 3.5 stars, one can include 3 star icons and 1 half-star icon
Example: https://fontawesome.com/icons/star-half?style=solid&from=io

Review the repository’s existing icon definitions and contribution guidance, then compare the requested shape with the linked Font Awesome example. Done means a `half-star` icon is available and supports the stated 3.5-star use case.

Written by the indexing model from the issue text.