Add configuration page

Configuration.md

@@ -0,0 +1,113 @@
+## Settings
+
+The `settings` block contains settings for the SSH server itself.
+
+### Fields
+
+- `ssh_dir` (optional, string): Directory where SSH keys are stored. Default is `~/.ssh`.
+- `listen_addr` (optional, string): Address on which the SSH server listens. Default is `:2222`.
+- `debug` (optional, bool): Enables or disables debug logging. Default is `false`.
+
+### Example
+```hcl
+settings {
+  ssh_dir = "/home/user/.ssh"
+  listen_addr = "0.0.0.0:22"
+  debug = true
+}
+```
+
+## Route
+
+The `route` block represents a virtual host configuration.
+
+### Fields
+
+- `name` (label, string): The name of the virtual host.
+- `backend` (string): The backend to use for the route  (e.g., `docker`, `serial`).
+- `match` (string): The regular expression to match for routing. The first capture group in the regular expression will be passed to the backend as the argument. If there's a named capture group with the name `arg`, that will be used as the argument instead. If there are no capture groups, the whole routing path will be used as the argument.
+- `settings` (object): Additional settings for the backend. These are different for each backend.
+- `permissions` (optional, object): Permissions map for the route. If this is missing, all users will be allowed to access all resources.
+
+### Example
+```hcl
+route "example" {
+  backend = "docker"
+  match = "docker\\.(.+)"
+  settings = {
+    command = ["/bin/bash"]
+  }
+  permissions = {
+    admins = {
+      allow = ["*"]
+    }
+    group1 = {
+      allow = ["container1", "container2"]
+      deny = ["container3", "admin_container*"]
+    }
+  }
+}
+```
+
+## Auth
+
+The `auth` block contains the authentication settings.
+
+### Fields
+
+- [`fail2ban`](#fail2ban) (block): Fail2Ban rate limiter settings.
+- [`user`](#user) (block, multiple): List of virtual users.
+
+### Example
+```hcl
+auth {
+  fail2ban {
+    limit = "10m"
+    attempts = 5
+  }
+
+  user "user1" {
+    password = "$argon2id..."
+    groups = ["admins"]
+    pubkeys = ["ssh-ed25519 AAA..."]
+  }
+}
+```
+
+## Fail2Ban
+
+The `fail2ban` block contains the Fail2Ban rate limiter settings.
+
+### Fields
+
+- `limit` (string): Time interval (e.g., `1h2m3s`).
+- `attempts` (int): Number of allowed attempts before banning.
+
+### Example
+```hcl
+# Allows 5 failed login attempts per 10 minute interval
+fail2ban {
+  limit = "10m"
+  attempts = 5
+}
+```
+
+## User
+
+The `user` block contains the configuration for a virtual user.
+
+### Fields
+
+- `name` (label, string): The username.
+- `password` (optional, string): The argon2id hash of the user's password (can be generated using `seashell --gen-hash`).
+- `groups` (optional, []string): The groups to which the user belongs.
+- `pubkeys` (optional, []string): Public keys for the user.
+
+### Example
+```hcl
+user "admin" {
+  password = "$argon2id..."
+  groups = ["admins"]
+  pubkeys = ["ssh-ed25519 AAA..."]
+}
+```