Tutorial fixes and updates (#3003)

* Find-and-replace: Add `@testable import CounterApp`

* Typo Fix: "you" -> "your"

* Typo fix: It's -> its

* Typo: `CounterFeature` -> `ContactsFeature`

* Find-and-replace: Switch from deprecated `.navigationBarTitle()` to `navigationTitle()`

* Typo: `using` -> `uses`

* Add `@testable import CounterApp` to the Composing Feature section

* Typo: `closet` -> `closest`

* Remove mention of now-unused forward slash syntax for case paths

Author: dafurman

Sources/ComposableArchitecture/Documentation.docc/Articles/StackBasedNavigation.md

@@ -285,7 +285,7 @@ struct ChildView: View {
 }
 ```
 
-When `self.dismiss()` is invoked, SwiftUI finds the closet parent view that is presented in the
+When `self.dismiss()` is invoked, SwiftUI finds the closest parent view that is presented in the
 navigation stack, and removes that state from the collection powering the stack. This can be 
 incredibly useful, but it is also relegated to the view layer. It is not possible to use 
 `dismiss` elsewhere, like in an observable object, which would allow you to have nuanced logic

Sources/ComposableArchitecture/Documentation.docc/Articles/TreeBasedNavigation.md

@@ -87,7 +87,7 @@ struct InventoryFeature {
 > Note: The key path used with `ifLet` focuses on the `@PresentationState` projected value since it 
 > uses the `$` syntax. Also note that the action uses a
 > [case path](http://github.com/pointfreeco/swift-case-paths), which is analogous to key paths but
-> tuned for enums, and uses the forward slash syntax.
+> tuned for enums.
 
 That's all that it takes to integrate the domains and logic of the parent and child features. Next
 we need to integrate the features' views. This is done by passing a binding of a store to one

Sources/ComposableArchitecture/Documentation.docc/Tutorials/MeetTheComposableArchitecture/01-Essentials/03-TestingYourFeatures/01-03-01-code-0001.swift

@@ -1,6 +1,8 @@
 import ComposableArchitecture
 import XCTest
 
+@testable import CounterApp
+
 @MainActor
 final class CounterFeatureTests: XCTestCase {
   func testCounter() async {

Sources/ComposableArchitecture/Documentation.docc/Tutorials/MeetTheComposableArchitecture/01-Essentials/03-TestingYourFeatures/01-03-01-code-0002.swift

@@ -1,6 +1,8 @@
 import ComposableArchitecture
 import XCTest
 
+@testable import CounterApp
+
 @MainActor
 final class CounterFeatureTests: XCTestCase {
   func testCounter() async {

Sources/ComposableArchitecture/Documentation.docc/Tutorials/MeetTheComposableArchitecture/01-Essentials/03-TestingYourFeatures/01-03-01-code-0004.swift

@@ -1,6 +1,8 @@
 import ComposableArchitecture
 import XCTest
 
+@testable import CounterApp
+
 @MainActor
 final class CounterFeatureTests: XCTestCase {
   func testCounter() async {

Sources/ComposableArchitecture/Documentation.docc/Tutorials/MeetTheComposableArchitecture/01-Essentials/03-TestingYourFeatures/01-03-01-code-0005.swift

@@ -1,6 +1,8 @@
 import ComposableArchitecture
 import XCTest
 
+@testable import CounterApp
+
 @MainActor
 final class CounterFeatureTests: XCTestCase {
   func testCounter() async {

Sources/ComposableArchitecture/Documentation.docc/Tutorials/MeetTheComposableArchitecture/01-Essentials/03-TestingYourFeatures/01-03-01-code-0006.swift

@@ -1,6 +1,8 @@
 import ComposableArchitecture
 import XCTest
 
+@testable import CounterApp
+
 @MainActor
 final class CounterFeatureTests: XCTestCase {
   func testCounter() async {

Sources/ComposableArchitecture/Documentation.docc/Tutorials/MeetTheComposableArchitecture/01-Essentials/03-TestingYourFeatures/01-03-02-code-0001-previous.swift

@@ -1,6 +1,8 @@
 import ComposableArchitecture
 import XCTest
 
+@testable import CounterApp
+
 @MainActor
 final class CounterFeatureTests: XCTestCase {
 }

Sources/ComposableArchitecture/Documentation.docc/Tutorials/MeetTheComposableArchitecture/01-Essentials/03-TestingYourFeatures/01-03-02-code-0001.swift

@@ -1,6 +1,8 @@
 import ComposableArchitecture
 import XCTest
 
+@testable import CounterApp
+
 @MainActor
 final class CounterFeatureTests: XCTestCase {
   func testTimer() async {

Sources/ComposableArchitecture/Documentation.docc/Tutorials/MeetTheComposableArchitecture/01-Essentials/03-TestingYourFeatures/01-03-02-code-0002.swift

@@ -1,6 +1,8 @@
 import ComposableArchitecture
 import XCTest
 
+@testable import CounterApp
+
 @MainActor
 final class CounterFeatureTests: XCTestCase {
   func testTimer() async {