fixup! feat: Add user configuration for all providers

Add users to the docs site

Author: dlipovetsky

docs/content/customization/generic/users.md

@@ -0,0 +1,56 @@
++++
+title = "Users"
++++
+
+Configure users for all machines in the cluster, the user's superuser capabilities using `sudo` user specifications, and the login authentication mechanism.
+
+> - SSH _authorized keys_ are just public SSH keys that are used to authenticate a login. See the [SSH man page](https://www.man7.org/linux/man-pages/man8/sshd.8.html#AUTHORIZED_KEYS_FILE_FORMAT) for more information.
+>
+> - For information on sudo user specifications, see the [sudo documentation](https://www.sudo.ws/docs/man/sudoers.man/#User_specification).
+>
+> - Local password authentication is disabled for the user by default. It is enabled only when a hashed password is provided.
+
+## Examples
+
+### Admin user with SSH public key login
+
+Creates a user with the name `admin`, grants the user the ability to run any command as the superuser, and allows you to login via SSH using the username and private key corresponding to the authorized public key.
+
+```yaml
+apiVersion: cluster.x-k8s.io/v1beta1
+kind: Cluster
+metadata:
+  name: <NAME>
+spec:
+  topology:
+    variables:
+      - name: clusterConfig
+        value:
+          users:
+            - name: admin
+                - sshAuthorizedKeys:
+                    - "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAua0lo8BiGWgvIiDCKnQDKL5uERHfnehm0ns5CEJpJw optional-comment"
+              sudo: "ALL=(ALL) NOPASSWD:ALL"
+```
+
+### Admin user with serial console password login
+
+Creates a user with the name `admin,` grants the user the ability to run any command as the superuser, and allows you to login via serial console using the username and password.
+
+> Note that this does not allow you to login via SSH using the username and password; in most cases, you must also configure the SSH server to allow password authentication.
+
+```yaml
+apiVersion: cluster.x-k8s.io/v1beta1
+kind: Cluster
+metadata:
+  name: <NAME>
+spec:
+  topology:
+    variables:
+      - name: clusterConfig
+        value:
+          users:
+            - name: admin
+              hashedPassword: "$y$j9T$UraH8eN4XvapXBmmSaUrP0$Nyxdf1cJDGZcp0WDKu.CFHprrkPG4ubirqSqiD43Ix3"
+              sudo: "ALL=(ALL) NOPASSWD:ALL"
+```