Add API to provide custom footer

[mikepenz]

• introduce API to provide custom footer

// custom header, divider, footer
LibrariesContainer(
  libraries = libraries,
  modifier = Modifier.fillMaxSize().padding(it),
  header = {
    item {
      Box(modifier = Modifier.fillMaxWidth().padding(16.dp), contentAlignment = Alignment.Center) {
        Text("Hello Header")
      }
    }
  },
  divider = { HorizontalDivider() },
  footer = {
    item {
      Box(modifier = Modifier.fillMaxWidth().padding(16.dp), contentAlignment = Alignment.Center) {
        Text("Hello Footer")
      }
    }
  }
)

[Copilot]

Pull Request Overview

This PR adds an API for providing a custom footer (with custom header and divider) to the LibrariesContainer component.

• Introduces an "Advanced Usage" section in the README.
• Provides sample Kotlin code demonstrating how to configure custom header, divider, and footer.

Files not reviewed (14)

• aboutlibraries-compose-m2/api/aboutlibraries-compose-m2.klib.api: Language not supported
• aboutlibraries-compose-m2/api/android/aboutlibraries-compose-m2.api: Language not supported
• aboutlibraries-compose-m2/api/jvm/aboutlibraries-compose-m2.api: Language not supported
• aboutlibraries-compose-m2/src/androidMain/kotlin/com/mikepenz/aboutlibraries/ui/compose/AndroidLibraries.kt: Language not supported
• aboutlibraries-compose-m2/src/commonMain/kotlin/com/mikepenz/aboutlibraries/ui/compose/Libraries.kt: Language not supported
• aboutlibraries-compose-m2/src/commonMain/kotlin/com/mikepenz/aboutlibraries/ui/compose/SharedLibraries.kt: Language not supported
• aboutlibraries-compose-m3/api/aboutlibraries-compose-m3.klib.api: Language not supported
• aboutlibraries-compose-m3/api/android/aboutlibraries-compose-m3.api: Language not supported
• aboutlibraries-compose-m3/api/jvm/aboutlibraries-compose-m3.api: Language not supported
• aboutlibraries-compose-m3/src/androidMain/kotlin/com/mikepenz/aboutlibraries/ui/compose/m3/AndroidLibraries.kt: Language not supported
• aboutlibraries-compose-m3/src/commonMain/kotlin/com/mikepenz/aboutlibraries/ui/compose/m3/Libraries.kt: Language not supported
• aboutlibraries-compose-m3/src/commonMain/kotlin/com/mikepenz/aboutlibraries/ui/compose/m3/SharedLibraries.kt: Language not supported
• app-desktop/src/jvmMain/kotlin/m2/main.kt: Language not supported
• app-desktop/src/jvmMain/kotlin/m3/main.kt: Language not supported