Rename package to swift-mustache (#27)

* Rename package to swift-mustache

* Update CI

Sources/Mustache/SequenceContext.swift

@@ -0,0 +1,54 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Hummingbird server framework project
+//
+// Copyright (c) 2021-2021 the Hummingbird authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See hummingbird/CONTRIBUTORS.txt for the list of Hummingbird authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+/// Context that current object inside a sequence is being rendered in. Only relevant when rendering a sequence
+struct MustacheSequenceContext: MustacheTransformable {
+    var first: Bool
+    var last: Bool
+    var index: Int
+
+    init(first: Bool = false, last: Bool = false) {
+        self.first = first
+        self.last = last
+        self.index = 0
+    }
+
+    /// Transform `MustacheContext`. These are available when processing elements
+    /// of a sequence.
+    ///
+    /// Format your mustache as follows to accept them. They look like a function without any arguments
+    /// ```
+    /// {{#sequence}}{{index()}}{{/sequence}}
+    /// ```
+    ///
+    /// Transforms available are `first`, `last`, `index`, `even` and `odd`
+    /// - Parameter name: transform name
+    /// - Returns: Result
+    func transform(_ name: String) -> Any? {
+        switch name {
+        case "first":
+            return self.first
+        case "last":
+            return self.last
+        case "index":
+            return self.index
+        case "even":
+            return (self.index & 1) == 0
+        case "odd":
+            return (self.index & 1) == 1
+        default:
+            return nil
+        }
+    }
+}