cats: add Context-Aware Touch-Screen (CATS) docs

• docs: add first version of CATS docs (picking from eclipse/oniro-blueprints/archive-meta-oniro-blueprints-cats@7f74bb07)
• cats: add hardware setup, source fetch
• Add doorlock blueprint docs reference and CATS usage docs
• cats: use yocto to build and flash OpenThread RCP
• cats: document switching between multiple screens

Relate-to: eclipse/oniro-core/blueprints#46
Relate-to: eclipse/oniro-core/blueprints#6 (closed)
Relate-to: eclipse/oniro-core/docs#104 (closed)
Relate-to: eclipse/oniro-core&4
Relate-to: eclipse/oniro-core&23

Signed-off-by: Bartosz Golaszewski brgl@bgdev.pl
Signed-off-by: Francesco Pham francesco.pham@huawei.com