Draft: flutter: Add layer

This revision belong to kirkstone branch.

It has been checked on onrio kirkstone base using downstream project:

https://gitlab.eclipse.org/eclipse/oniro-blueprints/experimental/flutter/meta-oniro-blueprints-flutter/

Relate-to: #669 (closed) Forwarded: !4 (closed) Relate-to: https://rzr.github.io/rzr-presentations/docs/oniro-community/#/18 Relate-to: https://gitlab.eclipse.org/pcoval/oniro-presentations/-/wikis/ Relate-to: https://booting.oniroproject.org/distro/oniro/-/merge_requests/541 Relate-to: https://gitlab.eclipse.org/pcoval/meta-oniro-blueprint-flutter/-/wikis/ Signed-off-by: Philippe Coval philippe.coval.ext@huawei.com

docs/supported-technologies/flutter.rst

+.. SPDX-FileCopyrightText: Huawei Inc.
+..
+.. SPDX-License-Identifier: CC-BY-4.0
+
+Flutter
+#######
+
+FLutter is an open-source framework to build modern 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:
+
+* `Flutter oniro blueprint <https://gitlab.eclipse.org/eclipse/oniro-blueprints/experimental/flutter/meta-oniro-blueprints-flutter>`__.
+* `Wiki about using flutter on Oniro <https://gitlab.eclipse.org/eclipse/oniro-blueprints/experimental/flutter/meta-oniro-blueprints-flutter/-/wikis>`__.
+* `Upstream OE/Yocto layer <https://github.com/meta-flutter/meta-flutter>`__.