Added alt text to documentation badge in readme

README.md

@@ -5,7 +5,7 @@
 📺[![tvOS](https://app.bitrise.io/app/0b037542c2395ffb/status.svg?token=yOtMqbu-5bj8grB1Jmoefg)](https://www.bitrise.io/app/0b037542c2395ffb)    
 ⌚️[![watchOS](https://app.bitrise.io/app/0d4d611f02295183/status.svg?token=NiLB_E_0IvYYqV4Mj973TQ)](https://www.bitrise.io/app/0d4d611f02295183)    
 <img src="https://upload.wikimedia.org/wikipedia/commons/3/3c/TuxFlat.svg" width="20" alt="Linux">[![](https://api.travis-ci.com/mapbox/turf-swift.svg?branch=main)](https://travis-ci.com/mapbox/turf-swift) &nbsp;&nbsp;&nbsp;
-[![](https://mapbox.github.io/turf-swift/2.0.0/badge.svg)](https://mapbox.github.io/turf-swift/) &nbsp;&nbsp;&nbsp;
+[![Documentation](https://mapbox.github.io/turf-swift/2.0.0/badge.svg)](https://mapbox.github.io/turf-swift/) &nbsp;&nbsp;&nbsp;
 [![Carthage compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](https://github.com/Carthage/Carthage) &nbsp;&nbsp;&nbsp;
 [![CocoaPods](https://img.shields.io/cocoapods/v/Turf.svg)](https://cocoapods.org/pods/Turf/) &nbsp;&nbsp;&nbsp;
 [![SPM compatible](https://img.shields.io/badge/SPM-compatible-4BC51D.svg?style=flat)](https://swift.org/package-manager/) &nbsp;&nbsp;&nbsp;