Issue 35093: Document the IDLE document viewer in the IDLE doc. (GH-10195)

Add a paragraph in "Help and preferences", "Help sources" subsection.
(cherry picked from commit 18032632ab27eed51d705c2be7b64bac708279bf)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

1 files changed, 20 insertions, 10 deletions

diff --git a/Doc/library/idle.rst b/Doc/library/idle.rst
index ba0640db..3bf87c2 100644
--- a/Doc/library/idle.rst
+++ b/Doc/library/idle.rst
@@ -295,7 +295,7 @@ About IDLE
    Display version, copyright, license, credits, and more.
 
 IDLE Help
-   Display a help file for IDLE detailing the menu options, basic editing and
+   Display this IDLE document, detailing the menu options, basic editing and
    navigation, and other tips.
 
 Python Docs
@@ -306,7 +306,8 @@ Turtle Demo
    Run the turtledemo module with example python code and turtle drawings.
 
 Additional help sources may be added here with the Configure IDLE dialog under
-the General tab.
+the General tab. See the "Help sources" subsection below for more
+on Help menu choices.
 
 .. index::
    single: Cut
@@ -693,15 +694,25 @@ with the default subprocess if at all possible.
 Help and preferences
 --------------------
 
-Additional help sources
-^^^^^^^^^^^^^^^^^^^^^^^
+Help sources
+^^^^^^^^^^^^
 
-IDLE includes a help menu entry called "Python Docs" that will open the
-extensive sources of help, including tutorials, available at docs.python.org.
-Selected URLs can be added or removed from the help menu at any time using the
-Configure IDLE dialog. See the IDLE help option in the help menu of IDLE for
-more information.
+Help menu entry "IDLE Help" displays a formatted html version of the
+IDLE chapter of the Library Reference.  The result, in a read-only
+tkinter text window, is close to what one sees in a web browser.
+Navigate through the text with a mousewheel,
+the scrollbar, or up and down arrow keys held down.
+Or click the TOC (Table of Contents) button and select a section
+header in the opened box.
+
+Help menu entry "Python Docs" opens the extensive sources of help,
+including tutorials, available at docs.python.org/x.y, where 'x.y'
+is the currently running Python version.  If your system
+has an off-line copy of the docs (this may be an installation option),
+that will be opened instead.
 
+Selected URLs can be added or removed from the help menu at any time using the
+General tab of the Configure IDLE dialog .
 
 Setting preferences
 ^^^^^^^^^^^^^^^^^^^
@@ -711,7 +722,6 @@ changed via Configure IDLE on the Option menu.  Keys can be user defined;
 IDLE ships with four built-in key sets. In addition, a user can create a
 custom key set in the Configure IDLE dialog under the keys tab.
 
-
 Extensions
 ^^^^^^^^^^