Inspector APIs Doc Updates (#12657)

Summary:
Pull Request resolved: #12657

This PR updates the Inspector APIs' documentation to introduce the calculate_numeric_gap for the executorch 0.7 release.

Differential Revision: D78595467

Author: Juntian777

devtools/inspector/_inspector.py

@@ -1385,8 +1385,7 @@ def calculate_numeric_gap(self, distance: str = "MSE") -> pd.DataFrame:
             distance: the metrics the inspector will use for gap calculation. Should be one of "MSE", "L1" and "SNR".
 
         Returns:
-            pd.DataFrame: A DataFrame listing corresponding operator outputs from
-                          both stages and their computed numerical gaps.
+            pd.DataFrame: A DataFrame listing corresponding operator outputs from both stages and their computed numerical gaps.
         """
         aot_intermediate_outputs, aot_debug_handle_to_op_names = (
             self._get_aot_intermediate_outputs_and_op_names()

docs/source/_static/img/calculate_numeric_gap.png

@@ -106,6 +106,22 @@ get_exported_program
     Equality constraints: []
 
 
+calculate_numeric_gap
+~~~~~~~~~~~~~~~~~~
+
+.. autofunction:: executorch.devtools.Inspector.calculate_numeric_gap
+
+.. _example-usage-4:
+
+**Example Usage:**
+
+.. code:: python
+
+    print(inspector.calculate_numeric_gap("L1"))
+
+.. image:: _static/img/calculate_numeric_gap.png
+This table compares the intermediate outputs of operations between ahead-of-time (AOT)  and runtime. The columns show debug handles, intermediate outputs from both AOT and runtime, and the L1(user defined) gap between them.  Later, we will change the debug_handle to operator names to better improve readability and interpretability of the results.
+
 Inspector Attributes
 --------------------