Merge pull request thephpleague#1455 from erikn69/patch-4

[DOC] Match readme.md adapters links with website docs

readme.md

@@ -17,17 +17,22 @@ for which ever storage is right for you.
 
 ## Getting Started
 
-* **[New in V2](https://flysystem.thephpleague.com/v2/docs/what-is-new/)**: What it new in Flysystem V2?
-* **[Architecture](https://flysystem.thephpleague.com/v2/docs/architecture/)**: Flysystem's internal architecture
-* **[Flysystem API](https://flysystem.thephpleague.com/v2/docs/usage/filesystem-api/)**: How to interact with your Flysystem instance
-* **[Upgrade to V2](https://flysystem.thephpleague.com/v2/docs/advanced/upgrade-to-2.0.0/)**: How to upgrade your Flysystem V1 instance to V2
-
-### Commonly-Used Adapters
-
-* **[AsyncAws S3](https://flysystem.thephpleague.com/v2/docs/adapter/async-aws-s3/)**
-* **[AWS S3](https://flysystem.thephpleague.com/v2/docs/adapter/aws-s3-v3/)**
-* **[Local](https://flysystem.thephpleague.com/v2/docs/adapter/local/)**
-* **[Memory](https://flysystem.thephpleague.com/v2/docs/adapter/in-memory/)**
+* **[New in V3](https://flysystem.thephpleague.com/docs/what-is-new/)**: What is new in Flysystem V2/V3?
+* **[Architecture](https://flysystem.thephpleague.com/docs/architecture/)**: Flysystem's internal architecture
+* **[Flysystem API](https://flysystem.thephpleague.com/docs/usage/filesystem-api/)**: How to interact with your Flysystem instance
+* **[Upgrade from 1x](https://flysystem.thephpleague.com/docs/upgrade-from-1.x/)**: How to upgrade from 1.x/2.x
+
+### Officially supported adapters
+
+* **[Local](https://flysystem.thephpleague.com/docs/adapter/local/)**
+* **[FTP](https://flysystem.thephpleague.com/docs/adapter/ftp/)**
+* **[SFTP](https://flysystem.thephpleague.com/docs/adapter/sftp-v3/)**
+* **[Memory](https://flysystem.thephpleague.com/docs/adapter/in-memory/)**
+* **[AWS S3](https://flysystem.thephpleague.com/docs/adapter/aws-s3-v3/)**
+* **[AsyncAws S3](https://flysystem.thephpleague.com/docs/adapter/async-aws-s3/)**
+* **[Google Cloud Storage](https://flysystem.thephpleague.com/docs/adapter/google-cloud-storage/)**
+* **[Azure Blob Storage](https://flysystem.thephpleague.com/docs/adapter/azure-blob-storage/)**
+* **[WebDAV](https://flysystem.thephpleague.com/docs/adapter/webdav/)**
 
 ### Third party Adapters