Add Arena support

Author: davdroman

.arena-sample.swift

@@ -0,0 +1,80 @@
+// Playground generated with 🏟 Arena (https://github.com/finestructure/arena)
+// ℹ️ If running the playground fails with an error "no such module ..."
+//    go to Product -> Build to re-trigger building the SPM package.
+// ℹ️ Please restart Xcode if autocomplete is not working.
+
+import SwiftUI
+import TextBuilder
+import PlaygroundSupport
+
+struct DemoView: View {
+    @State var name: String?
+
+    var body: some View {
+        VStack(spacing: 20) {
+            welcomeText.font(.title)
+            descriptionText
+            someClickableText
+            footnote
+        }
+        .multilineTextAlignment(.center)
+        .padding()
+        .background(Color(.windowBackgroundColor))
+    }
+
+    @SpacedTextBuilder
+    var welcomeText: Text {
+        if let name = name, !name.isEmpty {
+            "Welcome,"
+            name.text.bold()
+        } else {
+            "Welcome"
+        }
+    }
+
+    @BasicTextBuilder
+    var descriptionText: Text {
+        "This is a demo of "
+        "TextBuilder".text.italic()
+        "."
+    }
+
+    var someClickableText: Text {
+        Text(separator: " ") {
+            "This paragraph is implemented"
+            "without".text.underline()
+            "a builder to showcase the"
+            "Text.init(separator:content:)".text.font(.system(.body, design: .monospaced)).foregroundColor(.gray)
+            "initializer provided by this library."
+        }
+    }
+
+    var footnote: some View {
+        Text {
+            "Made by "
+            "@davdroman".text.bold()
+        }
+        .underline()
+        .font(.system(.caption))
+        .foregroundColor(.blue)
+        .pointable()
+        .onTapGesture { NSWorkspace.shared.open(URL(string: "https://github.com/davdroman/TextBuilder")!) }
+    }
+}
+
+extension View {
+    func pointable() -> some View {
+        onHover { inside in
+            if inside {
+                NSCursor.pointingHand.push()
+            } else {
+                NSCursor.pop()
+            }
+        }
+    }
+}
+
+let view = NSHostingController(rootView: DemoView(name: NSFullUserName()))
+view.view.frame.size.width = 340
+PlaygroundPage.current.needsIndefiniteExecution = true
+PlaygroundPage.current.liveView = view

README.md

@@ -102,3 +102,9 @@ var loremIpsum: Text {
     "amet, consectetur"
 }
 ```
+
+## Try it out!
+
+TextBuilder supports [Arena](https://github.com/finestructure/Arena) to effortlessly test this library in a playground before you decide to take it for a spin in your own project.
+
+Simply [install Arena](https://github.com/finestructure/Arena#how-to-install-arena) and run `arena davdroman/TextBuilder --platform macos` in your terminal.