Remove manual and update README

Author: Sparks29032

README.rst

@@ -82,7 +82,7 @@ and typing into a terminal window or Windows command prompt. It is
 recommended that you consult online resources and become somewhat
 familiar before using ``diffpy.morph``.
 
-``diffpy.morph`` can be run with Python 3.10 or higher. It makes use of several third party
+``diffpy.morph`` can be run with Python 3.11 or higher. It makes use of several third party
 libraries that you'll need to run the app and its components.
 
 * `NumPy`              - library for scientific computing with Python
@@ -140,8 +140,7 @@ You may consult our `online documentation <https://diffpy.github.io/diffpy.morph
 USING diffpy.morph
 ------------------
 
-For detailed instructions and full tutorial, consult the user manual
-on our `website <www.diffpy.org/diffpy.morph/>`.
+For detailed instructions and full tutorial, see our `website <www.diffpy.org/diffpy.morph/>`.
 
 Once the required software, including ``diffpy.morph`` is all installed, open
 up a terminal and check installation has worked properly by running ::
@@ -158,9 +157,8 @@ of ``diffpy.morph`` that you have installed on your system. To begin using
 
 where both PDFs file are text files which contain PDF data, such as ``.gr``
 or ``.cgr`` files that are produced by ``PDFgetX2``, ``PDFgetX3``,
-or ``PDFgui``. Though some file extensions other than ``.gr`` or ``.cgr``,
-but with the same content structure, have been shown to work with
-``diffpy.morph``, it is recommended to stick with ``.gr`` files.
+or ``PDFgui``. File extensions other than ``.gr`` or ``.cgr``,
+but with the same content structure, also work with ``diffpy.morph``.
 
 Enjoy!
 

doc/manual/README.txt

@@ -0,0 +1,3 @@
+This directory included files to build a PDF and HTML version of the diffpy.morph user manual.
+We are no longer maintaining the manual or this directory, but all files are intact for legacy reasons.
+All relevant information from the manual has been migrated to the website at https://www.diffpy.org/diffpy.morph.

src/diffpy/morph/morphapp.py

@@ -371,7 +371,8 @@ def custom_error(self, msg):
             "as follows: each target PDF is an entry in NAMESFILE. For each "
             "entry, there should be a key {__save_morph_as__} whose value "
             "specifies the name to save the manipulated PDF as. An example "
-            ".json serial file is shown in the diffpy.morph manual."
+            ".json serial file is included in the tutorial directory "
+            "on the package GitHub repository."
         ),
     )
     group.add_option(