Rename package to swift-mustache (#27)

* Rename package to swift-mustache

* Update CI

Sources/Mustache/Library+FileSystem.swift

@@ -0,0 +1,44 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+import Foundation
+
+extension MustacheLibrary {
+    /// Load templates from a folder
+    static func loadTemplates(from directory: String, withExtension extension: String = "mustache") async throws -> [String: MustacheTemplate] {
+        var directory = directory
+        if !directory.hasSuffix("/") {
+            directory += "/"
+        }
+        let extWithDot = ".\(`extension`)"
+        let fs = FileManager()
+        guard let enumerator = fs.enumerator(atPath: directory) else { return [:] }
+        var templates: [String: MustacheTemplate] = [:]
+        for case let path as String in enumerator {
+            guard path.hasSuffix(extWithDot) else { continue }
+            guard let data = fs.contents(atPath: directory + path) else { continue }
+            let string = String(decoding: data, as: Unicode.UTF8.self)
+            var template: MustacheTemplate
+            do {
+                template = try MustacheTemplate(string: string)
+            } catch let error as MustacheTemplate.ParserError {
+                throw ParserError(filename: path, context: error.context, error: error.error)
+            }
+            // drop ".mustache" from path to get name
+            let name = String(path.dropLast(extWithDot.count))
+            templates[name] = template
+        }
+        return templates
+    }
+}