docs: Fix some awkward phrasing in core.md (argoproj#17412)

Signed-off-by: Nate Douglas <[email protected]>
Signed-off-by: Mangaal <[email protected]>

docs/operator-manual/core.md

@@ -25,7 +25,7 @@ A few use-cases that justify running Argo CD Core are:
 
 - As a cluster admin, I want to rely on Kubernetes RBAC only.
 - As a devops engineer, I don't want to learn a new API or depend on
-  another CLI to automate my deployments. I want instead rely in
+  another CLI to automate my deployments. I want to rely on the
   Kubernetes API only.
 - As a cluster admin, I don't want to provide Argo CD UI or Argo CD
   CLI to developers.