Address @berendt's feedback.

In particular:
- Capitalize Reference Implementation and Ceph.
- Decapitalize the in-a from Cloud-in-a-Box.
- Remove extra 's' from Kubernetes-as-a-Service*s*.
- Use internal links where possible.

Signed-off-by: Kurt Garloff <[email protected]>

Author: garloff

docs/index.mdx

@@ -18,14 +18,14 @@ SCS is built, backed, and operated by an active open-source community worldwide.
 
 ### Virtualization (IaaS) Layer
 
-The SCS IaaS reference implementation is based on [OSISM](https://osism.tech/).
+The SCS IaaS Reference Implementation is based on [OSISM](https://osism.tech/).
 
-#### Quick Start with Cloud-In-A-Box
+#### Quick Start with Cloud-in-a-Box
 
 You can do a single node installation for learning, testing or development purposes.
-The Cloud-In-A-Box configuration was built explicitly for this scenario.
+The Cloud-in-a-Box configuration was built explicitly for this scenario.
 Check it out [here](/docs/iaas/deployment-examples/cloud-in-a-box)
-It comes with a complete set of services, even ceph is part of it
+It comes with a complete set of services, even Ceph is part of it
 (despite of course not offering much redundancy on a single-node).
 
 #### Reference Implementation Testbed
@@ -40,7 +40,7 @@ virtualization.
 
 Read the [testbed docs](/docs/iaas/deployment-examples/testbed) to learn how to get the
 testbed running. Please read carefully through the
-[deployment](https://osism.tech/docs/testbed#deployment) section of the
+[deployment](/docs/iaas/deployment-examples/testbed#deployment) section of the
 manual.
 
 #### Examples for real deployments
@@ -52,8 +52,8 @@ used hardware.
 
 ### Container Layer
 
-The Reference Implementation (v2) for the container (Kubernetes-as-a-Services = KaaS) layer
-is provided by [Cluster-Stacks](https://docs-staging.scs.community/docs/category/cluster-stacks)
+The Reference Implementation (v2) for the container (Kubernetes-as-a-Service = KaaS) layer
+is provided by [Cluster Stacks](/docs/category/cluster-stacks)
 from [syself](https://syself.com/).
 
 #### Cluster Stacks