Add operator documentation (BETWEEN, LIKE, IN, IS DISTINCT FROM)

[arnaud-lacurie]

Summary

Adds complete documentation for SQL operators: BETWEEN, LIKE, IN, and IS DISTINCT FROM.

Operators documented

• BETWEEN - Range testing with inclusive bounds
• LIKE - Pattern matching with wildcards (%, _) and ESCAPE clause
• IN - Value list membership testing
• IS DISTINCT FROM - NULL-safe equality comparison

Files

• BETWEEN.rst/diagram with comprehensive examples
• LIKE.rst/diagram with wildcard patterns and ESCAPE
• IN.rst/diagram with NULL handling details
• Updated Comparison.rst with IS DISTINCT FROM
• Updated Operators.rst index
• operators-documentation-queries.yamsql test file
• Updated DocumentationQueriesTests.java