Add ktlint plugin

buildSrc/build.gradle.kts

@@ -1,7 +1,7 @@
 plugins {
     `kotlin-dsl`
     kotlin("jvm") version "1.4.10"
-    id("com.github.johnrengelman.shadow") version "6.1.0"
+    id("com.github.johnrengelman.shadow") version "6.1.0" apply false
 }
 
 repositories {
@@ -12,4 +12,5 @@ repositories {
 dependencies {
     implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:1.4.10")
     implementation("com.github.jengelman.gradle.plugins:shadow:6.1.0")
+    implementation("org.jlleitschuh.gradle:ktlint-gradle:9.4.1")
 }

buildSrc/src/main/kotlin/be/simplenotes/base.gradle.kts

@@ -6,6 +6,7 @@ plugins {
     java
     kotlin("jvm")
     `java-library`
+    id("org.jlleitschuh.gradle.ktlint")
 }
 
 repositories {
@@ -21,6 +22,7 @@ version = "1.0-SNAPSHOT"
 
 dependencies {
     implementation(kotlin("stdlib-jdk8"))
+    implementation(platform("org.jetbrains.kotlin:kotlin-bom:1.4.10"))
 }
 
 tasks.withType<Test> {