doc: updated README to reflect the complete revision

[sttk]

This PR reflects the complete revision (#30) to README.md.

[Copilot]

Pull Request Overview

This PR fully revises README.md to align with the 0.4.0 release, updating badges, links, and the overall structure for clearer installation and usage guidance.

• Updated header badges to include Maven Central and refreshed link URLs.
• Rewrote Concept and Usage sections with step-by-step Java code examples.
• Refreshed license year and JDK/GraalVM version listings.

Comments suppressed due to low confidence (5)

README.md:1

• [nitpick] Remove the leading spaces before the H1 header so it renders correctly as a top‐level heading in Markdown.

# [Sabi][repo-url] [![Maven Central][mvn-img]][mvn-url] [![GitHub.io][io-img]][io-url] [![CI Status][ci-img]][ci-url] [![MIT License][mit-img]][mit-url]

README.md:11

• [nitpick] Rephrase for clarity: use “implement” instead of “fulfill” and refer to “interfaces” rather than “derived classes”, e.g. “concrete types that implement multiple DataAcc-derived interfaces.”

On the data access layer side, implementations can be provided by concrete types that fulfill multiple `DataAcc` derived classes. This allows for implementation in any arbitrary unit — whether by external data service, by table, or by functional concern.

README.md:66

• Add a closing ````` after this block to terminate the ```java code fence opened at line 56.

}

README.md:105

• Ensure you add a closing ````` to end the Java code block started at line 90.

}

README.md:42

• [nitpick] Add a language identifier to this code fence (e.g. ```groovy) for proper syntax highlighting of the Gradle snippet.

repositories {