Add language specifications to all code blocks

[leogdion]

Description

Add proper language specifications to all code blocks in documentation to enable syntax highlighting and improve readability.

Background

CodeRabbit review of PR #105 identified missing language specifications in code blocks throughout the documentation, which impacts readability and prevents proper syntax highlighting.

Tasks

• Audit all documentation files for code blocks without language specs
• Add appropriate language identifiers (swift, bash, json, etc.)
• Verify syntax highlighting works correctly
• Update any code examples that may be outdated

Code Block Examples

# Before

let config = MistKitConfiguration(...)

# After
```swift
let config = MistKitConfiguration(...)

## Acceptance Criteria
- [ ] All code blocks have appropriate language specifications
- [ ] Syntax highlighting renders correctly in GitHub
- [ ] Code examples are accurate and up-to-date

## Related
- PR #105 CodeRabbit feedback
- Part of documentation quality improvements

## Labels
documentation, enhancement, syntax-highlighting

[leogdion]

Addressed in README