docs: style customization updated (#106)

* Style customization doc updated

I believe the doc was not up to date regarding the cutomization of logger

* Update README.md

Co-authored-by: Ayman Bagabas <ayman.bagabas@gmail.com>

* Update README.md

Co-authored-by: Ayman Bagabas <ayman.bagabas@gmail.com>

---------

Co-authored-by: Ayman Bagabas <ayman.bagabas@gmail.com>

README.md

@@ -210,18 +210,18 @@ defined at a global level in [styles.go](./styles.go).
 
 ```go
 // Override the default error level style.
-log.ErrorLevelStyle = lipgloss.NewStyle().
- SetString("ERROR!!").
- Padding(0, 1, 0, 1).
- Background(lipgloss.AdaptiveColor{
- Light: "203",
- Dark: "204",
- }).
- Foreground(lipgloss.Color("0"))
+styles := log.DefaultStyles()
+styles.Levels[log.ErrorLevel] = lipgloss.NewStyle().
+ SetString("ERROR!!").
+ Padding(0, 1, 0, 1).
+ Background(lipgloss.Color("204")).
+ Foreground(lipgloss.Color("0"))
 // Add a custom style for key `err`
-log.KeyStyles["err"] = lipgloss.NewStyle().Foreground(lipgloss.Color("204"))
-log.ValueStyles["err"] = lipgloss.NewStyle().Bold(true)
-log.Error("Whoops!", "err", "kitchen on fire")
+styles.Keys["err"] = lipgloss.NewStyle().Foreground(lipgloss.Color("204"))
+styles.Values["err"] = lipgloss.NewStyle().Bold(true)
+logger := log.New(os.Stderr)
+logger.SetStyles(styles)
+logger.Error("Whoops!", "err", "kitchen on fire")
 ```
 
 <picture>