When Josh Detius first learned that a community garden was opening this fall along the Richmond Greenway near Unity Park, he was excited for the opportunity to put his skills to use. “I’d learned to garden and take care of plants at Diablo Valley College, so I knew what to do,” said Detius, who volunteers at the garden through VistAbility’s Commercial Support Services program in Richmond, which serves adults with developmental disabilities. Created in partnership with Richmond and agricultural nonprofit…