Use YAML format for config files

[jer-j]

Why?

Adopting YAML for configuration files offers several advantages:

• Complex Configuration Structure: Sioyek's configuration involves numerous settings, including colors, paths, user preferences, and additional commands. YAML's hierarchical structure and support for nested data make it well-suited for representing the intricate configuration schema that Sioyek requires.

• Readability for Users and Developers: Sioyek's user base likely includes both end-users and developers. YAML's human-readable syntax makes it easy for both groups to understand and modify configurations. This readability is crucial for users tweaking their settings and developers maintaining the codebase.

• Flexibility in Data Types: Sioyek's configurations encompass a variety of data types, such as strings, integers, floats, and colors. YAML's support for diverse data types allows for a more natural representation of these configurations, enhancing both clarity and expressiveness.

• Ease of Integration into C++ Code: YAML has well-supported libraries in various programming languages, including C++. Integrating a YAML parser into the C++ codebase of Sioyek would be straightforward, simplifying the process of reading and writing configuration files.

• Community Adoption: YAML is a well-established and widely adopted configuration format in the software development community. Leveraging a popular standard ensures that Sioyek users and contributors are already familiar with the chosen configuration format.

• Future Extensibility: YAML's readability and flexibility make it a future-proof choice. If Sioyek evolves and introduces new configuration options or features, YAML can easily accommodate these changes without sacrificing human readability.

As far as I can tell, this mainly affects the config.h and config.cpp files.

Why not?

• Large breaking change
• Would need to update a lot of documentation
• Could use JSON instead which could potentially be faster but less readable (but why? you're not working with javascript)
  (→ do in next release?)