feature: improve normalization logic for files to help synchronization logic

[sytone]

• Implemented normalization of file paths in Peer classes to prevent additional loops.
• Introduced useNormalizedCachePaths configuration option across peers to ensure consistent cache lookups.
• Enhanced README with detailed configuration options and explanations for new features.
• Updated Deno imports for compatibility and improved path handling.

This fixes #29

On Windows, the synchronization was causing additional loops due to inconsistent path separators in cache keys causing updates to be pushed to peers that should have been skipped.

Root Cause

On Windows:

• File watcher events from Deno provide paths with backslashes (\)
• Paths processed through toPosixPath() have forward slashes (/)
• The normalizeCacheKey() method wasn't normalizing separators
• Different code paths produced different separator styles for the same file
• BaseDir may have backslashes (\) or forward slashes (/) so that is also normalized.

This ensures that:

• "./vault/file.md" becomes "file.md"
• "vault\file.md" becomes "file.md" (Windows)
• "vault/file.md" becomes "file.md"
• baseDir is properly stripped regardless of format