Split "Highlight weekends" functionality into "Highlight Saturdays" and "Highlight Sundays"

[amalgame21]

Fix #65
I built the app with ./gradlew assembleDebug and tested the .apk on my pixel 8 successfully.

Type of change(s)

• Bug fix
• Feature / enhancement
• Infrastructure / tooling (CI, build, deps, tests)
• Documentation

What changed and why

Split "Highlight weekends" functionality into "Highlight Saturdays" and "Highlight Sundays"

Tests performed

Before & after preview

Closes the following issue(s)

• Closes #

Checklist

• I read the contribution guidelines.
• I manually tested my changes on device/emulator (if applicable).
• I updated the "Unreleased" section in CHANGELOG.md (if applicable).
• I have self-reviewed my pull request (no typos, formatting errors, etc.).
• All checks are passing.

[amalgame21]

It would be great if you can guide me through about the merge process because I have zero experience of android apps development and writing Kotlin code (this PR is my first attempt in Kotlin), thanks!

[naveensingh]

Thanks for the effort, but this isn't the right approach. It'll be added as proposed here.