Improve singleton code doc

[MADHURI-HS]

Added JavaDoc comments to improve clarity of the Singleton implementation.

This change enhances code readability by explaining the purpose of the getInstance() method and how it ensures a single instance throughout the application.

[github-actions]

PR Summary

Adds JavaDoc for singleton instance method; updates READMEs to reflect usage notes (event-driven observer implications and database connection example); clarifies IvoryTower singleton behavior with explicit getInstance() documentation.

Changes

File	Summary
observer/README.md	Added a new bullet noting that the Observer pattern is especially useful in event-driven systems where a change in one object should automatically reflect in multiple dependents.
singleton/README.md	Added a bullet indicating that database connection management systems can benefit from a singleton to ensure a single shared instance across the application.
singleton/src/main/java/com/iluwatar/singleton/IvoryTower.java	Enhanced class Javadoc to state the eagerly initialized, thread-safe singleton nature and added getInstance() documentation describing the single instance contract.

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autogenerated by presubmit.ai

[github-actions]

✅ LGTM!

Review Summary

Commits Considered (3)

• dce1b3c: Added JavaDoc for singleton instance method
• f2d8546: Improved observer pattern documentation with use case explaination
• d2a8516: Added database connection example to Singleton pattern

Files Processed (3)

• observer/README.md (1 hunk)
• singleton/README.md (1 hunk)
• singleton/src/main/java/com/iluwatar/singleton/IvoryTower.java (2 hunks)

Actionable Comments (0)

Skipped Comments (4)

• observer/README.md [177-177]

  readability: "Add usage context for Observer pattern"

• singleton/README.md [81-81]

  readability: "Improve README bullet for database singleton example"

• singleton/src/main/java/com/iluwatar/singleton/IvoryTower.java [27-31]

  readability: "Document singleton class contract"

• singleton/src/main/java/com/iluwatar/singleton/IvoryTower.java [50-56]

  readability: "Improve Javadoc for getInstance()"