Add more String extensions

WebsiteGenerator/Extensions/String+Extensions.swift

@@ -36,4 +36,20 @@ extension String {
         let parts = components(separatedBy: separator)
         return parts.dropLast().joined(separator: separator) + content + separator + parts.last!
     }
+
+    func dropAfterFirst<T>(_ separator: T) -> String where T: StringProtocol {
+        components(separatedBy: separator).first!
+    }
+
+    func between(_ start: String, and end: String) -> String {
+        dropBeforeFirst(start).dropAfterFirst(end)
+    }
+}
+
+extension Substring {
+
+    func between(_ start: String, and end: String) -> String {
+        components(separatedBy: start).last!
+            .components(separatedBy: end).first!
+    }
 }