Uses tree-sitter v0.20.9-beta-2 from fork (#327)

Author: simonbs

Example/Example.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -15,7 +15,7 @@ let package = Package(
     dependencies: [
         // Tree-sitter supports SPM but as of writing this, the official Tree-sitter repository has no versions published that contains the Package.swift file. Therefore, we depend on a fork of Tree-sitter that has a version published.
         // We will pin against the official version of Tree-sitter as soon as a new version is published.
-        .package(url: "https://github.com/simonbs/tree-sitter", from: "0.20.9-beta-1")
+        .package(url: "https://github.com/simonbs/tree-sitter", from: "0.20.9-beta-2")
     ],
     targets: [
         .target(name: "Runestone", dependencies: [