New pages for NCCR CLIM+ task submission and support

We have added two new pages describing how to request tasks and get support for the NCCR CLIM+ project.

• Requesting a Task explains how to submit a task using the CLIM+ task submission template and how to track its status on the CLIM+ project board.
• Support points to the CLIM+ support forum for questions related to the project.

Both require a GitHub account and membership in the CLIM+ user group within the C2SM organization.