The Forager skill has the chance to drop random items of your choice. By default it includes apples, bandages, scrap, water buckets, and metal fragments. These are just item I wrote in to get you started. You can remove these items and add your own custom list of items. To do this you will need to manually edit the config file (in game admin panel doesn't have this ability yet).

When you open the config file look for this section:

    "randomChanceList": {
      "0": {
        "shortname": "apple",
        "amount": 1
      },
      "1": {
        "shortname": "bandage",
        "amount": 1
      },
      "2": {
        "shortname": "scrap",
        "amount": 1
      },
      "3": {
        "shortname": "bucket.water",
        "amount": 1
      },
      "4": {
        "shortname": "metal.fragments",
        "amount": 1
      }
    }

You can edit the items in the list by changing the shortname to the item you want and control the amount of items that drop by changing the amount. To add more items to this list you need to add a new entry like this:

      "0": {  // Next number in the list
        "shortname": "apple", // Shortname of the item
        "amount": 1 // Amount to drop
      },

Make sure you continue to increase the next number and do not have any rereating numbers in the list. You can add as many items as you wish. The Forager skill will randomly choose one of the items in this list to drop when the skill activates.