docs: add rustdoc comments to all module options

This part of an upcoming effort to generate documentation from code.

Pushing this out before that stage so that the JSON schema is fully documented.

src/modules/script.rs

@@ -12,14 +12,29 @@ use tracing::error;
 #[derive(Debug, Deserialize, Clone)]
 pub struct ScriptModule {
     /// Path to script to execute.
+    ///
+    /// This can be an absolute path,
+    /// or relative to the working directory.
+    ///
+    /// **Required**
     cmd: String,
-    /// Script execution mode
+
+    /// Script execution mode.
+    /// See [modes](#modes) for more info.
+    ///
+    /// **Valid options**: `poll`, `watch`
+    /// <br />
+    /// **Default**: `poll`
     #[serde(default = "default_mode")]
     mode: ScriptMode,
+
     /// Time in milliseconds between executions.
+    ///
+    /// **Default**: `5000`
     #[serde(default = "default_interval")]
     interval: u64,
 
+    /// See [common options](module-level-options#common-options).
     #[serde(flatten)]
     pub common: Option<CommonConfig>,
 }