Fix Vale warnings in doc/install/

doc/install/aws/index.md

@@ -87,7 +87,7 @@ Implementation patterns may also provide specialized implementations beyond the
 
 For example:
 
-- Small, self-contained GitLab instances for per-person admin training, perhaps on Kubernetes so that a deployment cluster is self-contained as well.
+- Small, self-contained GitLab instances for per-person administration training, perhaps on Kubernetes so that a deployment cluster is self-contained as well.
 - GitLab Runner implementation patterns, including using platform-specific PaaS.
 
 ## Intended audiences and contributors

doc/install/azure/index.md

@@ -229,7 +229,7 @@ You can now visit GitLab with your browser at the new external URL.
 Use the domain name you set up earlier to visit your new GitLab instance
 in your browser. In this example, it's `https://gitlab-prod.eastus.cloudapp.azure.com`.
 
-The first thing that appears is the sign-in page. GitLab creates an admin user by default.
+The first thing that appears is the sign-in page. GitLab creates an administrator user by default.
 The credentials are:
 
 - Username: `root`