OAuth Server docs: Fix a wrong menu item name
Summary: Diviner's "Using the Phorge OAuth Server" article mentions "Create Application" but that item got renamed to "Create OAuth Server" in rP57f016b1.
Test Plan: Go to http://phorge.localhost/oauthserver/ and check the upper right corner.
Reviewers: O1 Blessed Committers, mainframe98
Reviewed By: O1 Blessed Committers, mainframe98
Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Differential Revision: https://we.phorge.it/D26194