Accept TL schema comments and fail generation on parse errors

Author: decoder-dev

build-system/SwiftTL/Sources/SwiftTL/DescriptionParsing.swift

@@ -20,6 +20,7 @@ enum DescriptionParser {
     private static let skipContains: [String] = ["{X:Type}"]
 
     private static func shouldSkipLine(_ line: String) -> Bool {
+        line.trimmingCharacters(in: .whitespaces).hasPrefix("//") ||
         skipPrefixes.contains { line.hasPrefix($0) } ||
         skipContains.contains { line.contains($0) }
     }

build-system/SwiftTL/Sources/SwiftTL/main.swift

@@ -104,4 +104,5 @@ do {
     }
 } catch let e {
     print("\(e)")
+    exit(1)
 }