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/clock.rs

@@ -17,23 +17,47 @@ use crate::{glib_recv, module_impl, send_async, spawn, try_send};
 
 #[derive(Debug, Deserialize, Clone)]
 pub struct ClockModule {
-    /// Date/time format string.
-    /// Default: `%d/%m/%Y %H:%M`
+    /// The format string to use for the date/time shown on the bar.
+    /// Pango markup is supported.
     ///
     /// Detail on available tokens can be found here:
     /// <https://docs.rs/chrono/latest/chrono/format/strftime/index.html>
+    ///
+    /// **Default**: `%d/%m/%Y %H:%M`
     #[serde(default = "default_format")]
     format: String,
 
+    /// The format string to use for the date/time shown in the popup header.
+    /// Pango markup is supported.
+    ///
+    /// Detail on available tokens can be found here:
+    /// <https://docs.rs/chrono/latest/chrono/format/strftime/index.html>
+    ///
+    /// **Default**: `%H:%M:%S`
     #[serde(default = "default_popup_format")]
     format_popup: String,
 
+    /// The locale to use when formatting dates.
+    ///
+    /// Note this will not control the calendar -
+    /// for that you must set `LC_TIME`.
+    ///
+    /// **Valid options**: See [here](https://docs.rs/pure-rust-locales/0.8.1/pure_rust_locales/enum.Locale.html#variants)
+    /// <br>
+    /// **Default**: `$LC_TIME` or `$LANG` or `'POSIX'`
     #[serde(default = "default_locale")]
     locale: String,
 
+    /// The orientation to display the widget contents.
+    /// Setting to vertical will rotate text 90 degrees.
+    ///
+    /// **Valid options**: `horizontal`, `vertical`
+    /// <br>
+    /// **Default**: `horizontal`
     #[serde(default)]
     orientation: ModuleOrientation,
 
+    /// See [common options](module-level-options#common-options).
     #[serde(flatten)]
     pub common: Option<CommonConfig>,
 }