username: add page (tldr-pages#17614)

Co-authored-by: Machiavelli <[email protected]>

Author: 2 people

pages/cisco-ios/username.md

@@ -0,0 +1,9 @@
+# username
+
+> Manage users.
+> Accessed in configuration mode.
+> More information: <https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/security/s1/sec-s1-xe-3se-3850-cr-book/sec-s1-xe-3se-3850-cr-book_chapter_0110.html>.
+
+- Set up an admin account:
+
+`username {{admin}} privilege 15 secret {{password}}`