skellam 0.2.4

New Features and Improvements

• Added a comprehensive README.md with usage examples, installation instructions, and badges (e.g., CRAN status, license).
• Improved the vignette (validate_skellam.Rmd) with clearer explanations, reproducible examples, and better visualizations.

Documentation Updates

• Revised documentation for skellam.reg to clarify parameter definitions, return values, and included practical examples.

Internal Changes

• Updated vignette-building dependencies (now requires rmarkdown and knitr).
• Minor fixes to ensure compatibility with R CMD check across all tested platforms (see cran-results.md).