Update link to the clients webpage, fix #15825 (#15874)

changelog.d/15874.misc

+Updated the link in home page from https://matrix.org/docs/projects/try-matrix-now.html#clients to https://matrix.org/ecosystem/clients/.

synapse/static/index.html

@@ -48,7 +48,7 @@
     </div>
     <h1>It works! Synapse is running</h1>
     <p>Your Synapse server is listening on this port and is ready for messages.</p>
-    <p>To use this server you'll need <a href="https://matrix.org/docs/projects/try-matrix-now.html#clients" target="_blank" rel="noopener noreferrer">a Matrix client</a>.
+    <p>To use this server you'll need <a href="https://matrix.org/ecosystem/clients/" target="_blank" rel="noopener noreferrer">a Matrix client</a>.
     </p>
     <p>Welcome to the Matrix universe :)</p>
     <hr>