Add simple_grasping release team

[mikeferguson]

• Name of the new release team: simple_grasping

• Release repositories to add:

  • simple_grasping
    • ros/rosdistro source entry
    • No existing release repository for ROS 2
  • grasping_msgs
    • ros/rosdistro source entry
    • There is an existing release repository which should be imported: https://github.com/mikeferguson/grasping_msgs-ros2-gbp

• Team members

  • @mikeferguson You'll notice both source repos are under my account

grasping_msgs is already released into humble/iron/jazzy - wanting to release into rolling, hence the moving of the GBP. simple_grasping was available in ROS 1, now getting it released into ROS 2 (especially since it is featured in an upcoming ROSCON talk later this month). I would normally just create a PR with the changes - but not sure how we do the import of an existing GBP.