[TASK] Break up "page/userTSconfig" as two words (TYPO3-Documentation…

…#3911)

see TYPO3-Documentation/TYPO3CMS-Reference-TSconfig#418 (review)

Documentation/ExtensionArchitecture/FileStructure/ExtLocalconf.rst

@@ -98,8 +98,8 @@ Read :ref:`why the check for the TYPO3 constant is necessary <globals-constants-
 
 .. index:: Extension development; PageTSconfig
 
-Adding default PageTSconfig
-~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Adding default page TSconfig
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 ..  versionchanged:: 12.0
     Page TSconfig in a file :file:`EXT:some_extension/Configuration/page.tsconfig`
@@ -117,8 +117,8 @@ file :file:`Configuration/TCA/Overrides/pages.php`, see
 
 .. index:: Extension development; UserTSconfig
 
-Adding default UserTSconfig
-~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Adding default user TSconfig
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 ..  deprecated:: 13.0
     The method