Signed-off-by: Matt Madison <matt@madison.systems>

To reference branch selection, based on discussion in

https://github.com/OE4T/tegra-demo-distro/issues/23#issuecomment-742541097



Signed-off-by: Dan Walkes <danwalkes@boulderai.com>

Also add reference to optional step to install pre-commit hook.

Signed-off-by: Dan Walkes <danwalkes@boulderai.com>

To support the upcoming OE4T contributor guide wiki page, add
a script which generates a pre-commit hook with Signed-off-by
message appended.

Signed-off-by: Dan Walkes <danwalkes@boulderai.com>

To reference distros supported.

Content imported from the old test distro, with the
following modifications:

* Removed most custom configuration files
* All open-source layers fully included under layers/
* Secureboot support removed
* Layout reworked to eliminate extra subdirectory for
  core layer
* Added meta-tegra-support layer for holding common
  metadata for use by all distro layers
* Reworked setup-env script to be usable for multiple
  distros sharing the repository
* Added demo image recipes and packagegroups

Signed-off-by: Matt Madison <matt@madison.systems>

Signed-off-by: Matt Madison <matt@madison.systems>