Update README, Update CI, Build on Swift 6

.github/workflows/ci.yml

···
         uses: actions/checkout@v5
       - uses: swift-actions/setup-swift@v2
         with:
-          swift-version: "6.0"
+          swift-version: "6.1"
       - name: Testing Package
         run: set -o pipefail && swift test | xcbeautify
       - name: Building Fuzzing Target

Package.swift

···
         ),
         .testTarget(
             name: "CBORTests",
-            dependencies: ["CBOR"],
+            dependencies: ["CBOR"]
         )
     ]
 )

README.md

···
-
-
 <p align="center">
   <img src="https://github.com/thecoolwinter/CBOR/blob/main/.github/Icon-256.png?raw=true" height="128">
   <h1 align="center">CBOR</h1>
 </p>
+
+<div align="center">
+  <a href="">![CI Status](https://img.shields.io/github/actions/workflow/status/thecoolwinter/CBOR/ci.yml)</a>
+</div>
 
 [CBOR](https://cbor.io/) is a flexible data format that emphasizes extremely small code size, small message size, and extendability. This library provides a Swift API for encoding and decoding Swift types using the CBOR serialization format. 
 

Sources/CBOR/Encoder/CBOREncoder.swift

···
     ///   - dateEncodingStrategy: See ``EncodingOptions/dateEncodingStrategy``.
     public init(
         forceStringKeys: Bool = false,
-        dateEncodingStrategy: EncodingOptions.DateStrategy = .double,
+        dateEncodingStrategy: EncodingOptions.DateStrategy = .double
     ) {
         options = EncodingOptions(
             forceStringKeys: forceStringKeys,