fix: use shadowJar gradle plugin

This allows to use icons in a fat jar

build.gradle

@@ -1,6 +1,7 @@
 plugins {
     id 'application'
     id 'org.openjfx.javafxplugin' version '0.0.9'
+    id 'com.github.johnrengelman.shadow' version '6.1.0'
 }
 
 group 'fr.insa.clavardator'
@@ -20,6 +21,8 @@ dependencies {
     runtimeOnly "org.openjfx:javafx-graphics:$javafx.version:linux"
     runtimeOnly "org.openjfx:javafx-graphics:$javafx.version:mac"
     implementation 'org.xerial:sqlite-jdbc:3.32.3'
+    implementation 'org.kordamp.ikonli:ikonli-javafx:12.0.0'
+    implementation 'org.kordamp.ikonli:ikonli-fontawesome5-pack:12.0.0'
     testImplementation("org.junit.jupiter:junit-jupiter-api:5.7.0")
     testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.7.0")
     compile 'com.jfoenix:jfoenix:9.0.10'
@@ -30,6 +33,8 @@ test {
     useJUnitPlatform()
 }
 
+mainClassName = 'fr.insa.clavardator.Launcher'
+
 jar {
     manifest {
         attributes 'Main-Class': 'fr.insa.clavardator.Launcher'
@@ -39,6 +44,10 @@ jar {
     }
 }
 
+shadowJar {
+    mergeServiceFiles()
+}
+
 run {
     jvmArgs = [
             "--add-exports=javafx.controls/com.sun.javafx.scene.control.behavior=ALL-UNNAMED",
@@ -48,5 +57,3 @@ run {
             "--add-exports=javafx.controls/com.sun.javafx.scene.control.behavior=ALL-UNNAMED"
     ]
 }
-
-mainClassName = 'fr.insa.clavardator.MainApp'