Update documentation

[sagikimhi]

Most of the current documentation is outdated and/or was generated and added by LLMs without a review (cuz im lazy and needed some docs)

Documentation needs to be updated with an effort to cover the following critical topics:

• A quickstart section covering prerequisites, installation, and basic commands
• A plugin user guide covering how to add python and script plugins and the differences between the 2 (a script plugin must be executable and is run as a subprocess, python plugins are run in-process and have the entire global and local namespace of socx-cli available which includes current runtime configuration values and other utilities)
• A configurations user guide briefly covering configuration options and how behaviour can be modified
• A regression user guide for running tests/regressions in parallel and configuration options for changing behaviour
• A configuration reference page documenting all of the default configurations, split by sections (i.e. git, regression, cli, etc.)