📝 Add docs annotations for source examples

docs_src/tutorial/update/annotations/en/tutorial002.md

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+1. Select the hero we will work with.
+
+2. Execute the query with the select statement object.
+
+    This generates the output:
+
+    ```
+    INFO Engine SELECT hero.id, hero.name, hero.secret_name, hero.age 
+    FROM hero 
+    WHERE hero.name = ?
+    INFO Engine [no key 0.00017s] ('Spider-Boy',)
+    ```
+
+3. Get one hero object, expecting exactly one.
+
+    !!! tip
+        This ensures there's no more than one, and that there's exactly one, not `None`.
+
+        This would never return `None`, instead it would raise an exception.
+
+4. Print the hero object.
+
+    This generates the output:
+
+    ```
+    Hero: name='Spider-Boy' secret_name='Pedro Parqueador' age=None id=2
+    ```
+
+5. Set the hero's age field to the new value `16`.
+
+    Now the `hero` object in memory has a different value for the age, but it is still not saved to the database.
+
+6. Add the hero to the session.
+
+    This puts it in that temporary place in the session before committing.
+
+    But it's still not saved in the database yet.
+
+7. Commit the session.
+
+    This saves the updated hero to the database.
+
+    And this generates the output:
+
+    ```
+    INFO Engine UPDATE hero SET age=? WHERE hero.id = ?
+    INFO Engine [generated in 0.00017s] (16, 2)
+    INFO Engine COMMIT
+    ```
+
+8. Refresh the hero object to have the recent data, including the age we just committed.
+
+    This generates the output:
+
+    ```
+    INFO Engine SELECT hero.id, hero.name, hero.secret_name, hero.age 
+    FROM hero 
+    WHERE hero.id = ?
+    INFO Engine [generated in 0.00018s] (2,)
+    ```
+
+9. Print the updated hero object.
+
+    This generates the output:
+
+    ```
+    Updated hero: name='Spider-Boy' secret_name='Pedro Parqueador' age=16 id=2
+    ```