Further revise idlelib/Icons/README.text (python#123364)

In particular, add trademark derivative approval information.

Lib/idlelib/Icons/README.txt

@@ -1,16 +1,23 @@
-2006?: Andrew Clover made the 16-, 32-, and 48-bit icons for win23.
+IDLE-PYTHON LOGOS
+
+These are sent to tk on Windows, *NIX, and non-Aqua macOS
+in pyshell following "# set application icon".
+
+
+2006?: Andrew Clover made variously sized python icons for win23.
 https://www.doxdesk.com/software/py/pyicons.html
-(TJR: Not sure if this originally included 256-bit image.)
 
-2006: They were copied to CPython as Python application icons.
+2006: 16, 32, and 48 bit .png versions were copied to CPython
+as Python application icons, maybe in PC/icons/py.ico.
 https://github.com/python/cpython/issues/43372
-(TJR: I do not remember where put in CPython source tree.)
 
 2014: They were copied (perhaps a bit revised) to idlelib/Icons.
 https://github.com/python/cpython/issues/64605
+.gif versions were also added.
 
 2020: Add Clover's 256-bit image.
 https://github.com/python/cpython/issues/82620
+Other fixups were done.
 
 The idle.ico file used for Windows was created with ImageMagick:
   $ convert idle_16.png idle_32.png idle_48.png idle_256.png idle.ico
@@ -19,18 +26,26 @@ The idle.ico file used for Windows was created with ImageMagick:
 
 Issue added Windows Store PC/icons/idlex44.png and .../idlex150.png.
 https://github.com/python/cpython/pull/22817
-** These should also be updated with major changes.
+?? Should these be updated with major changes?
 
-2022: Optimize .png images in CPython repository.
+2022: Optimize .png images in CPython repository with external program.
 https://github.com/python/cpython/pull/21348
 idle.ico (and idlex##) were not updated.
 
 The idlexx.gif files are only needed for *nix running tcl/tk 8.5.
 As of 2022, this was known true for 1 'major' Linux distribution.
-(Same would be true for any non-Aqua macOS with 8.5, but must be none.)
+(Same would be true for any non-Aqua macOS with 8.5, but now none?)
+Can be deleted when we require 8.6 or it is known always used.
+
+Future: Derivitives of Python logo should be submitted for approval.
+PSF Trademark Working Group / Committee psf-trademarks@python.org
+https://www.python.org/community/logos/  # Original files
+https://www.python.org/psf/trademarks-faq/
+https://www.python.org/psf/trademarks/  # Usage.
+
 
-The other .gifs are used by browsers using idlelib.tree.  At least some
-will not be used when tree is replaced by ttk.Treeview.
+OTHER GIFS: These are used by browsers using idlelib.tree.
+At least some will not be used when tree is replaced by ttk.Treeview.
 
 
-Edited 2024 August 25 by TJR.
+Edited 2024 August 26 by TJR.