Document releasing conda package and more

[xylar]

This pull request includes updates to documentation files for the mpas_tools conda package. The changes improve clarity, fix typos, and enhance the organization and completeness of the documentation. Key updates include corrections to naming conventions, expanded descriptions of functionality, and better usage examples.

Documentation Improvements

General Updates:

• Fixed typo in the README, changing mpas-tools to mpas_tools and added a note about limited updates to the conda package after September 2025.

Expanded Descriptions:

• Added a detailed table of methods provided by the MpasConfigParser class in config.rst, along with example usage for combining and managing configuration files.

Enhanced Usage Examples:

• Improved interpolation documentation in interpolation.rst, emphasizing the advantages of interp_bilin() over scipy for MPAS meshes and added notes about input grid bounds and geographic data handling. [1] [2]
• Updated mesh conversion documentation in mesh_conversion.rst to clarify input requirements, optional attributes, and Python usage for mesh conversion and cell culling workflows. [1] [2] [3] [4]

Organizational Changes:

• Added links to new sections in index.rst, including "quick_start" and "releasing," to improve navigation through the documentation. [1] [2]