docs: audit getting started guide

[demengc]

Summary

• Verified all API references (method names, signatures, import paths) against source code in BasePlugin, BaseSettings, Text, and Events
• Updated maven-shade-plugin (3.5.1 -> 3.6.1) and maven-compiler-plugin (3.11.0 -> 3.14.1) versions to match the project's own pom.xml
• Clarified that the -parameters compiler flag is specifically needed for Lamp command argument name discovery
• Added lifecycle method reference table documenting load(), enable(), and disable()
• Added complete BaseSettings reference table with all methods, defaults, and descriptions
• Expanded BaseSettings code example to show colorScheme() and includePrefixOnEachLine() overrides
• Replaced generic headings with descriptive, action-oriented ones
• Removed filler prose, redundant inline comments, and the empty "Build and Test" section
• Added GitBook YAML frontmatter
• Fixed XML indentation consistency in Maven dependency snippet

Test plan

• Verify markdown renders correctly in GitBook preview
• Confirm all code examples compile against current API
• Check that Maven/Gradle coordinates resolve via JitPack