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[Macosso]

This pull request updates the csdm package with improvements to documentation, package metadata, and code comments to enhance clarity and usability. The most significant changes include expanded and clarified documentation for the main estimation function, improved references using Rdpack, and updates to the package metadata for CRAN compliance and discoverability.

Documentation and Reference Improvements:

• Expanded and clarified the documentation for the csdm() function in R/csdm.R, including detailed descriptions of the supported estimators (MG, CCE, DCCE, CS-ARDL), model equations, assumptions, and usage of helper functions like csdm_csa() and csdm_lr(). References are now inserted using Rdpack for consistency. [1] [2]
• Updated references in R/utils_cd.R to use Rdpack's \insertRef{} syntax for better citation management.
• Improved and expanded the README with clearer explanations and mathematical notation for the four core estimators, their interpretation, and usage, making it easier for new users to understand the methodology. [1] [2]

Package Metadata and CRAN Compliance:

• Updated the DESCRIPTION file: incremented the version to 1.0.1, added Rdpack to Imports and RdMacros, included author ORCID, and added URL and BugReports fields for better package discoverability and CRAN policy compliance. [1] [2]
• Added a CRAN-SUBMISSION file for CRAN tracking and updated .Rbuildignore to exclude new documentation and configuration files from the build. [1] [2]

Code Imports and Namespace:

• Added Rdpack::reprompt to the NAMESPACE and import files to support the new reference and documentation system. [1] [2]

These changes collectively improve the clarity, reproducibility, and maintainability of the package, making it more accessible to users and compliant with CRAN standards.