Added GH workflow for building

.github/workflows/build.yml

@@ -0,0 +1,25 @@
+name: build
+on: [push, pull_request, workflow_dispatch]
+
+jobs:
+  build:
+    runs-on: ubuntu-22.04
+    if: ${{ github.event_name != 'pull_request' || github.repository != github.event.pull_request.head.repo.full_name }}
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v4
+      - name: Validate Gradle Wrapper
+        uses: gradle/wrapper-validation-action@v1
+      - name: Set up JDK 21
+        uses: actions/setup-java@v3
+        with:
+          distribution: temurin
+          java-version: 21
+          check-latest: true
+      - name: Build with Gradle
+        run: ./gradlew build
+      - name: Upload Artifacts to GitHub
+        uses: actions/upload-artifact@v3
+        with:
+          name: Artifacts
+          path: build/libs/

README.md

@@ -28,7 +28,7 @@ repositories {
 }
 
 dependencies {
-    implementation("net.raphimc:ViaLegacy:2.2.20") // Get latest version from releases
+    implementation("net.raphimc:ViaLegacy:x.x.x") // Get latest version from releases
 }
 ```
 
@@ -44,13 +44,13 @@ dependencies {
     <dependency>
         <groupId>net.raphimc</groupId>
         <artifactId>ViaLegacy</artifactId>
-        <version>2.2.20</version> <!-- Get latest version from releases -->
+        <version>x.x.x</version> <!-- Get latest version from releases -->
     </dependency>
 </dependencies>
 ```
 
 ### Jar File
-If you just want the latest jar file you can download it from this [Jenkins](https://ci.viaversion.com/view/All/job/ViaLegacy/).
+If you just want the latest jar file you can download it from [GitHub Actions](https://github.com/RaphiMC/ViaLegacy/actions/workflows/build.yml) or [Lenni0451's Jenkins](https://build.lenni0451.net/job/ViaLegacy/).
 
 ## Usage
 ViaLegacy requires you to have an already functional ViaVersion implementation for your platform.