Add product types for the created build tool plugin and command plugin packages

Most often these plugins are vended to other packages using products, so it makes sense to include this from the start.

Author: abertelrud

Sources/Workspace/InitPackage.swift

@@ -216,6 +216,15 @@ public final class InitPackage {
                             targets: ["\(pkgname)"]),
                     ]
                 """)
+            } else if packageType == .buildToolPlugin || packageType == .commandPlugin {
+                pkgParams.append("""
+                    products: [
+                        // Products define the executables and libraries a package produces, making them visible to other packages.
+                        .plugin(
+                            name: "\(pkgname)",
+                            targets: ["\(pkgname)"]),
+                    ]
+                """)
             } else if packageType == .macro {
                 pkgParams.append("""
                     products: [

Tests/WorkspaceTests/InitTests.swift

@@ -168,6 +168,7 @@ class InitTests: XCTestCase {
             let manifest = path.appending("Package.swift")
             XCTAssertFileExists(manifest)
             let manifestContents: String = try localFileSystem.readFileContents(manifest)
+            XCTAssertMatch(manifestContents, .and(.contains(".plugin("), .contains("targets: [\"MyCommandPlugin\"]")))
             XCTAssertMatch(manifestContents, .and(.contains(".plugin("), .contains("capability: .command(intent: .custom(verb")))
 
             let source = path.appending("Plugins", "MyCommandPlugin", "plugin.swift")
@@ -196,6 +197,7 @@ class InitTests: XCTestCase {
             let manifest = path.appending("Package.swift")
             XCTAssertFileExists(manifest)
             let manifestContents: String = try localFileSystem.readFileContents(manifest)
+            XCTAssertMatch(manifestContents, .and(.contains(".plugin("), .contains("targets: [\"MyBuildToolPlugin\"]")))
             XCTAssertMatch(manifestContents, .and(.contains(".plugin("), .contains("capability: .buildTool()")))
 
             let source = path.appending("Plugins", "MyBuildToolPlugin", "plugin.swift")