other/integeration_by_simpson_approx.py is added for approximate integeration (#1638)

* new file *iterating_through_submasks* is added in dynamic_programming section

* no changes

* *iterating_through_submasks.py is added in dynamic_programming

* iterating_through_submasks is added with doctests

* iterating_through_submasks.py is added in dynamic_programming

* changes made in *iterating_through_submasks.py

* changes made in *iterating_through_submasks.py

* updated

* *other/integeration_by_simpson_approx.py added

* *other/integeration_by_simpson_approx.py Added for integeration

* Delete iterating_through_submasks.py

* Delete DIRECTORY.md

* Revert "updated"

This reverts commit 73456f85de03782b7d3c794eca8390a4fe87037c.

* changes made *integeration_by_simpson_approx.py

* update2

Co-authored-by: Christian Clauss <cclauss@me.com>