Add missing docstrings to settings.rs (#9054)

Jadi created

![image](https://github.com/zed-industries/zed/assets/1290639/46c13110-8506-4b03-91d4-b1cfcafe824a)

Add documentation for theme-related settings.

Release Notes:

- Add documentation for theme-related settings ([8383](https://github.com/zed-industries/zed/issues/8383))

Change summary

crates/theme/src/settings.rs | 9 +++++++++
1 file changed, 9 insertions(+)

Detailed changes

crates/theme/src/settings.rs 🔗

@@ -155,22 +155,31 @@ impl ThemeSelection {
     }
 }
 
+/// Settings for rendering text in UI and text buffers.
 #[derive(Clone, Debug, Default, Serialize, Deserialize, JsonSchema)]
 pub struct ThemeSettingsContent {
+    /// The default font size for text in the UI.
     #[serde(default)]
     pub ui_font_size: Option<f32>,
+    /// The name of a font to use for rendering in the UI.
     #[serde(default)]
     pub ui_font_family: Option<String>,
+    /// The OpenType features to enable for text in the UI.
     #[serde(default)]
     pub ui_font_features: Option<FontFeatures>,
+    /// The name of a font to use for rendering in text buffers.
     #[serde(default)]
     pub buffer_font_family: Option<String>,
+    /// The default font size for rendering in text buffers.
     #[serde(default)]
     pub buffer_font_size: Option<f32>,
+    /// The buffer's line height.
     #[serde(default)]
     pub buffer_line_height: Option<BufferLineHeight>,
+    /// The OpenType features to enable for rendering in text buffers.
     #[serde(default)]
     pub buffer_font_features: Option<FontFeatures>,
+    /// The name of the Zed theme to use.
     #[serde(default)]
     pub theme: Option<ThemeSelection>,