IDLE Readme: Update file and menu lists

[terryjreedy]

[erlend-aasland]

Resolved with:

• gh-95638: Update idlelib README file and menu lists #95639
• [3.11] gh-95638: Update idlelib README file and menu lists (GH-95639) #95640
• [3.10] gh-95638: Update idlelib README file and menu lists (GH-95639) #95641