pythongh-128481: Improve documentation for traceback.FrameSummary (python#128484)

Complete the `traceback.FrameSummary` signature and add missing
documentation for the `colno` and `end_{col,line}no` attributes.

Author: Damien-Chen

Doc/library/traceback.rst

@@ -508,7 +508,9 @@ the module-level functions described above.
 A :class:`!FrameSummary` object represents a single :ref:`frame <frame-objects>`
 in a :ref:`traceback <traceback-objects>`.
 
-.. class:: FrameSummary(filename, lineno, name, lookup_line=True, locals=None, line=None)
+.. class:: FrameSummary(filename, lineno, name, *,\
+                        lookup_line=True, locals=None,\
+                        line=None, end_lineno=None, colno=None, end_colno=None)
 
    Represents a single :ref:`frame <frame-objects>` in the
    :ref:`traceback <traceback-objects>` or stack that is being formatted
@@ -544,6 +546,22 @@ in a :ref:`traceback <traceback-objects>`.
       trailing whitespace stripped.
       If the source is not available, it is ``None``.
 
+   .. attribute:: FrameSummary.end_lineno
+
+      The last line number of the source code for this frame.
+      By default, it is set to ``lineno`` and indexation starts from 1.
+
+   .. attribute:: FrameSummary.colno
+
+      The column number of the source code for this frame.
+      By default, it is ``None`` and indexation starts from 0.
+
+   .. attribute:: FrameSummary.end_colno
+
+      The last column number of the source code for this frame.
+      By default, it is ``None`` and indexation starts from 0.
+
+
 .. _traceback-example:
 
 Examples of Using the Module-Level Functions