docs: update analysis method to use ast.analyze() and enhance result destructuring

Author: isSerge

README.md

@@ -70,11 +70,13 @@ assert!(roles.contains("admin"));
 ### 2. Full analysis pass
 
 When you need all fields at once — accessed variables, local variables, and
-string comparisons — call `analyze_ast` directly to avoid multiple traversals:
+string comparisons — call `ast.analyze()` (or the equivalent free function
+`analyze_ast(&ast)`). Destructuring the result moves each field out without
+any extra cloning:
 
 ```rust
 use rhai::Engine;
-use rhai_analyzer::analyze_ast;
+use rhai_analyzer::{RhaiAnalyzerExt, ScriptAnalysisResult};
 
 let engine = Engine::new();
 let ast = engine.compile(r#"
@@ -84,16 +86,18 @@ let ast = engine.compile(r#"
     }
 "#).unwrap();
 
-let result = analyze_ast(&ast);
+let ScriptAnalysisResult { accessed_variables, local_variables, string_comparisons } =
+    ast.analyze();
 
-assert!(result.accessed_variables.contains("request.amount"));
-assert!(result.local_variables.contains("status"));
-assert!(result.string_comparisons["user.role"].contains("admin"));
+assert!(accessed_variables.contains("request.amount"));
+assert!(local_variables.contains("status"));
+assert!(string_comparisons["user.role"].contains("admin"));
 ```
 
 ### 3. Result data structure
 
 ```rust,ignore
+pub struct ScriptAnalysisResult {
     /// All unique, fully-qualified variable paths accessed in the script.
     pub accessed_variables: HashSet<String>,