fix incomplete and confusing website cover title (#4497)

- added missing "storage for" in the website cover title.
- without these words, it feels Cortex is a replacement for Prometheus.

Signed-off-by: Ranganath Kini <[email protected]>

Author: codematix

website/config.toml

@@ -53,7 +53,7 @@ id = "UA-63872299-2"
 [languages]
 [languages.en]
 title = "Cortex"
-description = "A horizontally scalable, highly available, multi-tenant, long term Prometheus."
+description = "A horizontally scalable, highly available, multi-tenant, long term storage for Prometheus."
 languageName ="English"
 # Weight used for sorting.
 weight = 1

website/content/en/_index.html

@@ -4,7 +4,7 @@
 
 +++
 
-{{< blocks/cover title="Horizontally scalable, highly available, multi-tenant, long term Prometheus." image_anchor="top" height="full" color="white" >}}
+{{< blocks/cover title="Horizontally scalable, highly available, multi-tenant, long term storage for Prometheus." image_anchor="top" height="full" color="white" >}}
 <div class="mx-auto">
 	<a class="btn btn-lg btn-primary mr-3 mb-4" href="{{< relref "/docs" >}}">
 		Learn More <i class="fas fa-arrow-alt-circle-right ml-2"></i>