Update README.md

Author: malczuuu

README.md

@@ -1,6 +1,5 @@
 # Problem4J Core
 
-[![JitPack](https://jitpack.io/v/malczuuu/problem4j-core.svg)](https://jitpack.io/#malczuuu/problem4j-core)
 [![Build Status](https://github.com/malczuuu/problem4j-core/actions/workflows/gradle-build.yml/badge.svg)](https://github.com/malczuuu/problem4j-core/actions/workflows/gradle-build.yml)
 
 > Part of [`problem4j`][problem4j] package of libraries.
@@ -63,27 +62,18 @@ manager.
 
 1. Maven:
    ```xml
-   <repositories>
-       <repository>
-           <id>jitpack.io</id>
-           <url>https://jitpack.io</url>
-       </repository>
-   </repositories>
    <dependencies>
        <dependency>
-           <groupId>com.github.malczuuu</groupId>
+           <groupId>io.github.malczuuu.problem4j</groupId>
            <artifactId>problem4j-core</artifactId>
            <version>${problem4j-core.version}</version>
        </dependency>
    </dependencies>
    ```
 2. Gradle (Groovy or Kotlin DSL):
    ```groovy
-   repositories {
-       maven { url = uri("https://jitpack.io") }
-   }
    dependencies {
-       implementation("com.github.malczuuu:problem4j-core:${problem4j-core.version}")
+       implementation("io.github.malczuuu.problem4j:problem4j-core:${problem4j-core.version}")
    }
     ```