Move extension to Sample.

See #362 (comment)

Author: yo1995

Shared/Supporting Files/Models/Sample.swift

@@ -41,6 +41,12 @@ protocol Sample {
 // MARK: Computed Variables
 
 extension Sample {
+    /// The URL to a sample's sub-directory on GitHub main branch.
+    var gitHubURL: URL {
+        URL(string: "https://github.com/Esri/arcgis-maps-sdk-swift-samples/tree/main/Shared/Samples")!
+            .appendingPathComponent(name)
+    }
+    
     /// The URL to a sample's `README.md` file.
     var readmeURL: URL {
         Bundle.main.url(forResource: name, withExtension: "md", subdirectory: "READMEs")!

Shared/Supporting Files/Views/SampleDetailView.swift

@@ -86,7 +86,7 @@ struct SampleDetailView: View {
         .toolbar {
             ToolbarItemGroup(placement: .topBarTrailing) {
 #if targetEnvironment(macCatalyst)
-                Link("View on GitHub", destination: .samplesDirectory.appendingPathComponent(sample.name))
+                Link("View on GitHub", destination: sample.gitHubURL)
 #endif
                 Button {
                     isSampleInfoViewPresented = true
@@ -112,10 +112,3 @@ struct SampleDetailView: View {
 extension SampleDetailView: Identifiable {
     var id: String { sample.nameInUpperCamelCase }
 }
-
-private extension URL {
-    /// The URL to the Samples sub-directory on GitHub's main branch.
-    static let samplesDirectory = URL(
-        string: "https://github.com/Esri/arcgis-maps-sdk-swift-samples/tree/main/Shared/Samples"
-    )!
-}