Doc: Revise 'Get and Install Qt' page for 6.10

As part of the onboarding documentation revision, especially for new users,
the consensus is to focus on Qt Quick and hide information related to widgets.

In this patch:
-Changed the versions
-Improved language
-Removed "Copying a Qt installation to another host"

Fixes: QTBUG-138436
Pick-to: 6.10
Change-Id: Ib7fbaa9b7f21c2b020e7ec0aa66fba961493d8ea

Reviewed-by: Kai Köhne <kai.koehne@qt.io>

doc/src/getting-started/get-and-install-qt.qdoc

@@ -30,7 +30,7 @@
 
     \list 1
         \li Select \uicontrol{Downloads}
-        \li Download \QOI for your host: Linux, macOS, or Windows
+        \li Download \QOI for your host: Linux (ARM64 or x64), macOS, or Windows (ARM64 or x64)
     \endlist
 
     See \l{Get and Install Qt with \QOI} for more information
@@ -43,9 +43,8 @@
 
     \section1 Using \QMT
 
-    Once Qt is installed, you can use \QMT under <install_dir>
-    to add components and to update or remove installed components. \QMT is
-    included in each Qt installation.
+    After you install Qt, you can use \QMT under <install_dir> to
+    add, update, or remove installed components.
 
     For more information about how to use \QMT with the command line
     interface, see \l{Get and Install Qt with Command Line Interface}.
@@ -61,13 +60,4 @@
     obtaining the Qt source code, information about Qt's prerequisites,
     and guidelines on configuring and building Qt.
 
-    \section1 Copying a Qt installation to another host
-
-    It's best practice to perform a clean installation on each host that uses
-    Qt. However, if you need to copy a Qt installation to another host, you
-    need to do some extra configuring for the commercial license check to work
-    properly. To ensure that the commercial license check works as expected
-    in the copied Qt installation, carry out the steps in
-    \l {Copying a Qt or QA installation to another computer}.
-
 */