Add notes how 'select' is implemented

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Fix developers procedure and add Dockerfile

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Fix test for JSON conversion

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Add multi-level select

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>
Update TODO list

Signed-off-by: Zlatozar Zhelyazkov <zlatozar@gmail.com>