Merge pull request #4386 from platformsh/4287-clarify-how-resources-work-on-upsun

feat: added paragraph about resources

Author: flovntp

sites/upsun/src/manage-resources/_index.md

@@ -16,4 +16,14 @@ keywords:
 {{% vendor/name %}} allows you to configure resources (CPU, RAM, and disk) per environment for each of your apps and services.
 You can also add instances for each of your apps depending on your needs.
 
-For information on costs related to resource usage, see the [{{% vendor/name %}} pricing page](https://upsun.com/pricing/).
+For information on costs related to resource usage, see the [{{% vendor/name %}} pricing page](https://upsun.com/pricing/).
+
+## How resources work on Upsun
+
+Projects on Upsun run on shared hosts, which means the processing power allocated to your containers can be dependent on resources other customers are using on the same hosts. Our orchestration layer works to ensure stable access to resources when possible, however some variability should be expected due to the shared infrastructure of our regions.
+
+{{< note theme="info" >}}
+
+ It should be noted that projects are always kept **strictly isolated** from each other. 
+
+{{< /note >}}