README: Fix another broken link (#1664)

README.md

@@ -84,7 +84,7 @@ And that's it! You are good to go 👍
 
 ### Next step
 
-Take a look at the [Getting Started](docs/getting-started/README.md) guide to learn more about how to extend the functionality with Plugins.
+Take a look at the [Getting Started](docs/getting-started/index.md) guide to learn how to set up Backstage, and how to develop on the platform.
 
 ## Documentation
 
@@ -106,7 +106,7 @@ We would love your help in building Backstage! See [CONTRIBUTING](CONTRIBUTING.m
 - [RFCs](https://github.com/spotify/backstage/labels/rfc) - Help shape the technical direction
 - [FAQ](docs/FAQ.md) - Frequently Asked Questions
 - [Code of Conduct](CODE_OF_CONDUCT.md) - This is how we roll
-- [Adopters](ADOPTERS.md)
+- [Adopters](ADOPTERS.md) - Companies already using Backstage
 - [Blog](https://backstage.io/blog/) - Announcements and updates
 - [Newsletter](https://mailchi.mp/spotify/backstage-community)
 - Give us a star ⭐️ - If you are using Backstage or think it is an interesting project, we would love a star ❤️