Add docs

Author: Kuuuube

src/nodes.rs

@@ -226,7 +226,8 @@ pub enum NodeValue {
     /// Enabled with the `alerts` option.
     Alert(Box<NodeAlert>),
 
-    ///
+    /// **Block**. Block scoped subscript that acts similar to a header.
+    /// Enabled with `subtext` option.
     Subtext,
 }
 

src/parser/options.rs

@@ -510,7 +510,20 @@ pub struct Extension<'c> {
     #[cfg_attr(feature = "bon", builder(default))]
     pub cjk_friendly_emphasis: bool,
 
+    /// Enables block scoped subscript that acts similar to a header.
     ///
+    /// ```md
+    /// -# subtext
+    /// ```
+    ///
+    /// ```rust
+    /// # use comrak::{markdown_to_html, Options};
+    /// let mut options = Options::default();
+    /// options.extension.subscript = true;
+    ///
+    /// assert_eq!(markdown_to_html("-# subtext", &options),
+    ///           "<p><sub>subtext</sub></p>\n");
+    /// ```
     pub subtext: bool,
 }