FIX: Adds documentation

xlsx/examples/hello_styles.rs

@@ -0,0 +1,22 @@
+use ironcalc::{base::model::Model, export::save_to_xlsx};
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let mut model = Model::new_empty("hello_styles", "en", "UTC")?;
+
+    // We are going to change styles in cell A1
+    let sheet = 0;
+    let row = 1;
+    let column = 1;
+    let mut style = model.get_style_for_cell(sheet, row, column);
+    style.fill.fg_color = Some("#FFEE11".to_string());
+    style.font.b = true;
+    style.font.color = Some("#EEFF22".to_string());
+    model.set_cell_style(sheet, row, column, &style)?;
+
+    // evaluates (unnecessary in this case)
+    model.evaluate();
+
+    // saves to disk
+    save_to_xlsx(&model, "hello-styles.xlsx")?;
+    Ok(())
+}