Update c26820.md

Updated examples to better reflect common use cases

Author: dmitrykobets

docs/code-quality/c26820.md

@@ -31,13 +31,15 @@ This check covers non-obvious and easy-to-miss behavior when assigning a referen
 This sample shows a variable definition that makes a potentially expensive copy when assigned a reference:
 
 ```cpp
-MyClass& ref = ...;
-auto var = ref; // C26820 (`var` takes a copy of the object referred to by `ref`)
+const Object& MyClass::getRef() { ... }
+...
+auto ref = myclass.getRef(); // C26820 (`ref` takes a copy of the returned object)
 ```
 
 To resolve this issue, declare the variable by using `const auto&` instead:
 
 ```cpp
-MyClass& ref = ...;
-const auto& var = ref; // OK
+const Object& MyClass::getRef() { ... }
+...
+const auto& ref = myclass.getRef(); // OK
 ```