Improve README.md

[qurbonzoda]

The changes were developed within GSoC 2023 program by our mentee @wldeh. To facilitate review process:

• The overhauled README focuses on setting up a Kotlin Multiplatform project for writing benchmarks and configuring their execution.
• There will be separate guides on setting up a Kotlin/JVM project or adding a benchmark module in an existing project.
• The non-existing documents referenced in this guide will be added in the followup PRs
• The README describes the next release (0.4.10) with https://github.com/Kotlin/kotlinx-benchmark/pull/163 , https://github.com/Kotlin/kotlinx-benchmark/pull/164 , https://github.com/Kotlin/kotlinx-benchmark/pull/165 , https://github.com/Kotlin/kotlinx-benchmark/pull/166 included