docs: Add LVGL supported tech

Relate-to: https://gitlab.eclipse.org/pcoval/oniro-presentations/-/wikis/blueprints Signed-off-by: Philippe Coval philippe.coval.ext@huawei.com

docs/supported-technologies/lvgl.rst

+.. SPDX-FileCopyrightText: Huawei Inc.
+..
+.. SPDX-License-Identifier: CC-BY-4.0
+
+LVGL
+####
+
+LVGL is an open-source library to build users interface.
+Originally designed for micro controllers, this toolkit can be also used on Linux flavour of Oniro
+using wayland backend.
+
+As reference example check Oniro Vending Machine blueprint, and its configuration flags,
+to build single fullscreen application.
+
+External Resources
+******************
+
+For more details on LVGL check:
+
+* `upstream LVGL documentation <https://docs.lvgl.io/>`__.
+* `FOSDEM presentation about LVGL <https://fosdem.org/2022/schedule/event/lvgl/>`__ and its integration into Oniro.
+* `Standalone example <https://gitlab.eclipse.org/pcoval/dialog-lvgl>`__ used for integration validation.
+* `OpenEmbedded recipes <http://cgit.openembedded.org/meta-openembedded/log/meta-oe/recipes-graphics/lvgl>`__ used in linux flavours of Oniro.
+* `Bootchart article <https://gitlab.eclipse.org/pcoval/oniro-presentations/-/wikis/bootchart>`__ about profiling LVGL device.