This script uses/imports a modified version of great customMenuItem of @jonB (see this topic )
It is modified to allow insertion of a new menu option where we want, not only at end (append) of the popup menu.
For instance, Find before Help

The new script find_in_files_new_menu.py will search a text in all your scripts via a new Findoption in the popup menu, without passing via the Help menu. In this case, we can't use the process of the help, thus the script shows its TableView of sources and a selected source is displayed in a @mikael 's WKWebView.
If you tap Find without selecting a text first, the program will ask you which text to search. This allows you to search a text non present in your edited file.
source is here find_in_files_new_menu.py.
Don't forget that this script has to be executed only once by Pythonista (re)start
