McuSupport: Update documentation

Task-number: QTCREATORBUG-25587
Change-Id: Ida9fb5449818c1c4b78318a6e9d85672153c19ad
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

doc/qtcreator/src/mcu/creator-mcu-dev.qdoc

@@ -44,7 +44,7 @@
 
     The toolchains are available for cross-compilation on Microsoft Windows,
     Linux, and macOS. However, the Qt for MCU SDK is currently only available
-    for Windows.
+    for Windows and Linux.
 
     For a list of Qt for MCU reference implementations, see the
     \l{Qt for MCUs - Supported Target Platforms}{Qt for MCUs} documentation.
@@ -54,7 +54,7 @@
     To use \QC to develop QML applications for MCUs, you need the following:
 
     \list
-        \li Qt for MCU SDK (only available for Windows)
+        \li Qt for MCU SDK (only available for Windows and Linux)
         \li \l{https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-rm}
             {GNU ARM Embedded Toolchain}
     \endlist
@@ -120,14 +120,17 @@
             \endlist
         \li Select the
             \uicontrol {Automatically create kits for all available targets on start}
-            option to create kits automatically.
-            \note You could also use \uicontrol {Create Kit} or
-                 \uicontrol{Remove Kit} to manually create or remove kits for the chosen
-                 target.
+            option to create kits automatically the next time Qt Creator is
+            started.
+            \note You could also use \uicontrol {Create Kit} to manually
+            create kits for the chosen target.
         \li Select \uicontrol Apply to save the settings.
     \endlist
-    \note You must restart \QC if you chose to create kits automatically
-          for all the available targets.
+
+    \note When updating to other versions of the Qt for MCUs SDK, \QC will
+    ask you if you want to replace the existing kits, or create new ones
+    alongside. This can also be done manually, for each individual target,
+    via \uicontrol {Update Kit} and \uicontrol {Create Kit}, respectively.
 
     \section2 Adding MCU Devices
 
@@ -150,30 +153,23 @@
            \li Select \uicontrol Apply to add the device.
        \endlist
 
-    \section2 Adding MCU Kits
+    \section2 Managing MCU Kits
 
-    \note This optional step is not necessary if you have already
-    set up the MCU SDK as outlined in \l{Specifying MCU Settings}.
-
-    \QC automatically adds kits for all the available targets, if
-    the
+    \QC automatically adds kits for all the available targets, if the
     \uicontrol {Automatically create kits for all available targets on start}
-    option is enabled under the \uicontrol MCU settings tab.
+    option is enabled under the \uicontrol MCU settings tab. You can also
+    create kits for individual targets manually, as outlined
+    in \l{Specifying MCU Settings}.
 
     \image qtcreator-mcu-kit.png "MCU kits"
 
-    To add kits, select \uicontrol Tools > \uicontrol Options > \uicontrol Kits
-    > \uicontrol Add:
+    You can edit and/or remove individual kits in \uicontrol Tools >
+    \uicontrol Options > \uicontrol Kits.
 
-    \list 1
-        \li In the \uicontrol Name field, specify a name for the kit.
-        \li In the \uicontrol {Device type} field, select
-            \uicontrol {MCU}.
-        \li In the \uicontrol Device field, select the MCU board for the kit.
-        \li In the \uicontrol Compiler field, select the Arm GCC compiler for
-            the kit.
-        \li Select \uicontrol Apply to add the kit.
-    \endlist
+    However, for adding new kits you should use the \uicontrol {Create Kit}
+    button in the {Qt for MCUs} settings tab. This method adds the paths to
+    the kit's toolkits and SDKs, and keeps them synchronized when selecting
+    \uicontrol Apply or \uicontrol OK.
 
     \section1 Running Applications on MCUs