Migrate dependency GitHub links from apple org to swiftlang org (#18)

Author: deivitaka

Package.resolved

@@ -12,7 +12,7 @@
     {
       "identity" : "swift-docc-plugin",
       "kind" : "remoteSourceControl",
-      "location" : "https://github.com/apple/swift-docc-plugin",
+      "location" : "https://github.com/swiftlang/swift-docc-plugin",
       "state" : {
         "revision" : "26ac5758409154cc448d7ab82389c520fa8a8247",
         "version" : "1.3.0"
@@ -21,7 +21,7 @@
     {
       "identity" : "swift-docc-symbolkit",
       "kind" : "remoteSourceControl",
-      "location" : "https://github.com/apple/swift-docc-symbolkit",
+      "location" : "https://github.com/swiftlang/swift-docc-symbolkit",
       "state" : {
         "revision" : "b45d1f2ed151d057b54504d653e0da5552844e34",
         "version" : "1.0.0"
@@ -48,7 +48,7 @@
     {
       "identity" : "swift-syntax",
       "kind" : "remoteSourceControl",
-      "location" : "https://github.com/apple/swift-syntax.git",
+      "location" : "https://github.com/swiftlang/swift-syntax.git",
       "state" : {
         "revision" : "303e5c5c36d6a558407d364878df131c3546fad8",
         "version" : "510.0.2"

Package.swift

@@ -14,10 +14,10 @@ let package = Package(
     ],
     dependencies: [
         .package(
-            url: "https://github.com/apple/swift-syntax.git",
+            url: "https://github.com/swiftlang/swift-syntax.git",
             from: "510.0.0"
         ),
-        .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.3.0"),
+        .package(url: "https://github.com/swiftlang/swift-docc-plugin", from: "1.3.0"),
         .package(url: "https://github.com/SwiftPackageIndex/SPIManifest.git", from: "0.12.0"),
         .package(url: "https://github.com/pointfreeco/swift-macro-testing", from: "0.4.0"),
     ],