> Supported boards moved to new folder
> Titles updated as per review for code and tools downloading
> References and link issue fixed

Detailed boards documents live in docs/supported-boards
repository. Remove them from here and reference the
supported-boards repo instead.

Signed-off-by: Arul Devarajan <arulkumaran.devarajan@huawei.com>

Update docs/source/overview/figures/.gitkeep, docs/source/overview/figures/architecture.png, docs/source/overview/figures/data_management.png, docs/source/overview/figures/device_virtual.png, docs/source/overview/figures/muti-device.png, docs/source/overview/figures/system_security.jpg, docs/source/overview/figures/task_scheduling.png, docs/source/overview/figures/virtual_bus.png, docs/source/overview/.gitkeep, docs/source/overview/Readme-EN.rst, docs/source/overview/about-harmonyOS.rst, docs/source/overview/system-security.rst, docs/source/overview/technical-features.rst, docs/source/quickstart/images/architecture.png, docs/source/quickstart/.gitkeep, docs/source/quickstart/Readme-EN.rst, docs/source/quickstart/build-open-harmony.rst, docs/source/readme/Images/.gitkeep, docs/source/readme/Images/Font_style.PNG, docs/source/readme/Images/List-table.PNG, docs/source/readme/Images/List.PNG, docs/source/readme/Images/csv_table.PNG, docs/source/readme/Images/math.PNG, docs/source/readme/Images/multi-column_list.PNG, docs/source/readme/Images/multi_data.PNG, docs/source/readme/Images/tables.PNG, docs/source/readme/Images/tables22.png, docs/source/readme/Images/toctree.PNG, docs/source/readme/.gitkeep, docs/source/readme/C Coding Style Guide.rst files