Provide page on Java security libraries

[jgadsden]

Summary :

Adds page for the OWASP Java security libraries:

• OWASP Java Encoder project
• OWASP Java HTML Sanitizer project
• OWASP JSON Sanitizer project

Description for the changelog :

Add Java security libraries

Declaration:

Thanks for submitting a pull request, please make sure:

• content meets the license for this project
• you have read the contribution guide and agree to the Code of Conduct
• either no AI-generated content has been used in this pull request
• or any use of AI in this pull request has been disclosed below:
  • AI Tools: [e.g. GitHub CoPilot, ChatGPT, JetBrains Junie, etc]
  • LLMs and versions: [e.g. GPT-4.1, Claude Haiku 4.5, Gemini 2.5 Pro, etc]
  • Prompts: [Summarize the key prompts or instructions given to the AI tools]

Other info :

Closes #181