Gradle task name to follow conventions (starting lowercase `aarch64` for ARM64)

README.md

@@ -94,9 +94,9 @@ A fat JAR for running on a x86_64 GNU/Linux server can be compiled with
 
     ./gradlew x86LinuxJar
 
-And also AArch64 with
+And also ARM64 with
 
-    ./gradlew ARM64LinuxJar
+    ./gradlew aarch64LinuxJar
 
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mailbox-cli/build.gradle

@@ -119,7 +119,7 @@ task x86LinuxJar(type: Jar) {
     jarFactory(it, 'linux', 'x86_64', configurations.runtimeClasspath)
 }
 
-task ARM64LinuxJar(type: Jar) {
+task aarch64LinuxJar(type: Jar) {
     group = "Build"
     description = "Assembles a runnable fat jar for AArch64 Linux"
     jarFactory(it, 'linux', 'aarch64', configurations.runtimeClasspath)