docs: comprehensive documentation for HAN-387

- README.md: full project overview, installation, quick start, CLI reference,
  output format descriptions, architecture overview, and dnstraverse comparison
- GoDoc: package-level documentation for traverse, dns, config, output, and
  fingerprint packages
- GoDoc: TraverserConfig and TraversalResult type comments in traverser.go

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: multica-agent <github@multica.ai>

internal/output/formatter.go

@@ -1,3 +1,13 @@
+// Package output renders ExploreDNS traversal results for human consumption or
+// machine processing.
+//
+// Two formats are supported:
+//
+//   - FormatText — a coloured hierarchical tree (default)
+//   - FormatJSON — a JSON array of traversal results
+//
+// Create a Formatter via NewFormatter and call RunTraversal to drive the
+// traversal engine and stream output incrementally.
 package output
 
 import (