Initial post

[Isaac Saito]

# Same content I posted in the old ROS GUI ML.

Currently I sent invitations to the maintainers of all the rqt related
pkgs I could think of.

There may or may not be active discussion in the future; the purpose I
would expect is:
- General contact point for rqt (github is pkg-based)
- rqt internal announcement for release timing
- Enhancement

Isaac