[ECO-1780] Removes broken feature matrix link

Removes broken feature matrix link - will be replaced in the future with an updated feature checklist.

README.md

@@ -8,7 +8,7 @@
 
 _[Ably](https://ably.com) is the platform that powers synchronized digital experiences in realtime. Whether attending an event in a virtual venue, receiving realtime financial information, or monitoring live car performance data – consumers simply expect realtime digital experiences as standard. Ably provides a suite of APIs to build, extend, and deliver powerful digital experiences in realtime for more than 250 million devices across 80 countries each month. Organizations like Bloomberg, HubSpot, Verizon, and Hopin depend on Ably’s platform to offload the growing complexity of business-critical realtime data synchronization at global scale. For more information, see the [Ably documentation](https://ably.com/docs)._
 
-This is a PHP REST client library for Ably. The library currently targets the [Ably 1.1 client library specification](https://www.ably.com/docs/client-lib-development-guide/features/). You can jump to the '[Known Limitations](#known-limitations)' section to see the features this client library does not yet support or [view our client library SDKs feature support matrix](https://www.ably.com/download/sdk-feature-support-matrix) to see the list of all the available features.
+This is a PHP REST client library for Ably. The library currently targets the [Ably 1.1 client library specification](https://www.ably.com/docs/client-lib-development-guide/features/). You can jump to the '[Known Limitations](#known-limitations)' section to see the features this client library does not yet support.
 
 
 ## Supported Platforms