Refer to web signup in README

Author: jpcoenen

README.md

@@ -4,7 +4,7 @@
 <br/>
 
 <p align="center">
-  <a href="https://secrethub.io/docs/start/getting-started/"><img alt="Get Started" src="https://secrethub.io/img/buttons/github/get-started.png?v1" height="28" /></a>
+  <a href="https://signup.secrethub.io/"><img alt="Get Started" src="https://secrethub.io/img/buttons/github/get-started.png?v1" height="28" /></a>
   <a href="https://secrethub.io/docs/reference/cli/"><img alt="View Docs" src="https://secrethub.io/img/buttons/github/view-docs.png?v2" height="28" /></a>
 </p>
 <br/>
@@ -23,7 +23,7 @@ The SecretHub CLI provides the command-line interface to interact with the Secre
 
 ## Get started
 
-Follow the [Getting Started Guide][getting-started] to quickly get up and running with SecretHub :rocket:
+[Set up SecretHub on your machine](https://signup.secrethub.io/) to quickly get up and running :rocket:
 
 ## Usage