docs(chart): document chart module (#696)

Author: Valentin271

src/symbols.rs

@@ -398,12 +398,12 @@ pub mod braille {
 /// Marker to use when plotting data points
 #[derive(Debug, Default, Display, EnumString, Clone, Copy, Eq, PartialEq, Hash)]
 pub enum Marker {
-    /// One point per cell in shape of dot ("•")
+    /// One point per cell in shape of dot (`•`)
     #[default]
     Dot,
-    /// One point per cell in shape of a block ("█")
+    /// One point per cell in shape of a block (`█`)
     Block,
-    /// One point per cell in the shape of a bar ("▄")
+    /// One point per cell in the shape of a bar (`▄`)
     Bar,
     /// Use the [Unicode Braille Patterns](https://en.wikipedia.org/wiki/Braille_Patterns) block to
     /// represent data points.
@@ -412,9 +412,9 @@ pub enum Marker {
     ///
     /// Note: Support for this marker is limited to terminals and fonts that support Unicode
     /// Braille Patterns. If your terminal does not support this, you will see unicode replacement
-    /// characters (�) instead of Braille dots.
+    /// characters (`�`) instead of Braille dots (`⠓`, `⣇`, `⣿`).
     Braille,
-    /// Use the unicode block and half block characters ("█", "▄", and "▀") to represent points in
+    /// Use the unicode block and half block characters (`█`, `▄`, and `▀`) to represent points in
     /// a grid that is double the resolution of the terminal. Because each terminal cell is
     /// generally about twice as tall as it is wide, this allows for a square grid of pixels.
     HalfBlock,