Amazon WAF Implementation Guide blog related FAQ

This question was targeted at collect following blog's questions

1. Amazon WAF Implementation Guide (1) WAF priciple, default implemtation and log store
2. Amazon WAF Implementation Guide (2) A cost effective way - Log Insight
3. Amazon WAF Implementation Guide (3) Leverage OpenSearch to start security investigation
4. Amazon WAF Implementation Guide (4) Use Log Hub solution to start WAF security operation