feat(config): Add support for inverted token in style strings (#2589)

* Add support for `reverse` keyword in style strings

* Duplicate test case and keep original

* Rename keyword to `inverted`

* Add explanatory sentence in readme

src/config.rs

@@ -359,7 +359,8 @@ impl StarshipConfig {
  - 'underline'
  - 'bold'
  - 'italic'
- - '<color>'        (see the parse_color_string doc for valid color strings)
+ - 'inverted'
+ - '<color>'       (see the parse_color_string doc for valid color strings)
 */
 pub fn parse_style_string(style_string: &str) -> Option<ansi_term::Style> {
     style_string
@@ -383,6 +384,7 @@ pub fn parse_style_string(style_string: &str) -> Option<ansi_term::Style> {
                     "bold" => Some(style.bold()),
                     "italic" => Some(style.italic()),
                     "dimmed" => Some(style.dimmed()),
+                    "inverted" => Some(style.reverse()),
                     // When the string is supposed to be a color:
                     // Decide if we yield none, reset background or set color.
                     color_string => {
@@ -675,7 +677,7 @@ mod tests {
     }
 
     #[test]
-    fn table_get_styles_bold_italic_underline_green_dimmy_silly_caps() {
+    fn table_get_styles_bold_italic_underline_green_dimmed_silly_caps() {
         let config = Value::from("bOlD ItAlIc uNdErLiNe GrEeN diMMeD");
         let mystyle = <Style>::from_config(&config).unwrap();
         assert!(mystyle.is_bold);
@@ -693,6 +695,27 @@ mod tests {
         );
     }
 
+    #[test]
+    fn table_get_styles_bold_italic_underline_green_dimmed_inverted_silly_caps() {
+        let config = Value::from("bOlD ItAlIc uNdErLiNe GrEeN diMMeD InVeRTed");
+        let mystyle = <Style>::from_config(&config).unwrap();
+        assert!(mystyle.is_bold);
+        assert!(mystyle.is_italic);
+        assert!(mystyle.is_underline);
+        assert!(mystyle.is_dimmed);
+        assert!(mystyle.is_reverse);
+        assert_eq!(
+            mystyle,
+            ansi_term::Style::new()
+                .bold()
+                .italic()
+                .underline()
+                .dimmed()
+                .reverse()
+                .fg(Color::Green)
+        );
+    }
+
     #[test]
     fn table_get_styles_plain_and_broken_styles() {
         // Test a "plain" style with no formatting