docs: Restructure Main Page

    * Restructure main page

    * Supported-technologies folder moved one level up

    * This is part of MR: https://booting.oniroproject.org/distro/docs/-/merge_requests/227

    * Rework on the documentation flow

    * Closes:  https://git.ostc-eu.org/distro/docs/-/issues/80



Signed-off-by: Gururaj Shetty <gururaj.shetty@huawei.com>

docs/index.rst

@@ -6,15 +6,38 @@ Build System Guide
 ##################
 
 .. toctree::
-   :maxdepth: 1
-      
+   :caption: Quick Start
+   :maxdepth: 2
+
    oniro-quick-build
-   yocto-build-system/index
-   repo-workspace
+
+.. toctree::
+   :caption: Oniro Project Blueprints
+   :maxdepth: 2
+
+   Oniro Project Blueprints <https://docs.oniroproject.org/projects/blueprints>
+
+.. toctree::
+   :caption: Build System Guide
+   :maxdepth: 2
+
+   Overview <yocto-build-system/index>
+   Creating Workspace <repo-workspace>
    build-flavours/index
    oniro-build/index
    os/index
    ci/index
    supported-images
    hardware-support/index
-   fallback-devices-support
+
+.. toctree::
+   :caption: Supported Technologies
+   :maxdepth: 2
+
+   supported-technologies/openthread
+
+.. toctree::
+   :caption: Troubleshoot
+   :maxdepth: 2
+
+   fallback-devices-support 

docs/os/index.rst

@@ -14,4 +14,3 @@ details various aspects for each kernel type.
    :maxdepth: 2
 
    linux/index
-   supported-technologies/index

docs/os/supported-technologies/index.rst

-.. SPDX-FileCopyrightText: Huawei Inc.
-..
-.. SPDX-License-Identifier: CC-BY-4.0
-
-.. include:: ../../definitions.rst
-
-.. _SupportedTechnologies:
-
-Supported Technologies
-######################
-
-This section details the supported technologies in |main_project_name|.
-
-.. toctree::
-   :maxdepth: 1
-   
-   openthread