Add DocC support

Example/HelloWorld.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -0,0 +1,25 @@
+{
+  "object": {
+    "pins": [
+      {
+        "package": "SwiftDocCPlugin",
+        "repositoryURL": "https://github.com/apple/swift-docc-plugin",
+        "state": {
+          "branch": null,
+          "revision": "26ac5758409154cc448d7ab82389c520fa8a8247",
+          "version": "1.3.0"
+        }
+      },
+      {
+        "package": "SymbolKit",
+        "repositoryURL": "https://github.com/apple/swift-docc-symbolkit",
+        "state": {
+          "branch": null,
+          "revision": "b45d1f2ed151d057b54504d653e0da5552844e34",
+          "version": "1.0.0"
+        }
+      }
+    ]
+  },
+  "version": 1
+}

Package.resolved

@@ -0,0 +1,23 @@
+{
+  "pins" : [
+    {
+      "identity" : "swift-docc-plugin",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-docc-plugin",
+      "state" : {
+        "revision" : "26ac5758409154cc448d7ab82389c520fa8a8247",
+        "version" : "1.3.0"
+      }
+    },
+    {
+      "identity" : "swift-docc-symbolkit",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-docc-symbolkit",
+      "state" : {
+        "revision" : "b45d1f2ed151d057b54504d653e0da5552844e34",
+        "version" : "1.0.0"
+      }
+    }
+  ],
+  "version" : 2
+}

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.5
+// swift-tools-version: 5.6
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
@@ -19,8 +19,7 @@ let package = Package(
             targets: ["Aptabase"]),
     ],
     dependencies: [
-        // Dependencies declare other packages that this package depends on.
-        // .package(url: /* package url */, from: "1.0.0"),
+        .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.3.0"),
     ],
     targets: [
         // Targets are the basic building blocks of a package. A target can define a module or a test suite.