Vendor NodePackage wrapper

...and deprecate it upstream

Sources/D2Commands/Math/LatexRenderer.swift

@@ -15,6 +15,6 @@ class LatexRenderer {
 
     private func renderPNG(from formula: String, color: String, scale: Double) async throws -> Data {
         log.debug("Invoking latex-renderer")
-        return try await node.start(withArgs: [formula, "--color", color, "--scale", String(scale)]).get()
+        return try await node.start(withArgs: [formula, "--color", color, "--scale", String(scale)])
     }
 }

Sources/D2Commands/NodePackage.swift

@@ -0,0 +1,17 @@
+import Foundation
+import Utils
+
+/// A wrapper around an executable node package that is located in the `Node`
+/// folder of this repository.
+public struct NodePackage {
+    private let directoryURL: URL
+
+    public init(name: String) {
+        directoryURL = URL(fileURLWithPath: "Node/\(name)")
+    }
+
+    /// Invokes `npm start` with the given arguments.
+    public func start(withArgs args: [String]) async throws -> Data {
+        try await Shell().output(for: "npm", in: directoryURL, args: ["run", "--silent", "start", "--"] + args).get()
+    }
+}