[Build] Add workflows for automatic releases

build.gradle

@@ -1,3 +1,5 @@
+import tool.UpVersion
+
 allprojects {
     group 'imgui-java'
     version property('version')
@@ -5,3 +7,18 @@ allprojects {
         mavenCentral()
     }
 }
+
+tasks.register('upVersion', UpVersion)
+
+tasks.register('buildAll') { t ->
+    t.group = 'build'
+    t.description = 'Build all project sources.'
+
+    t.dependsOn ':imgui-app:shadowJar'
+
+    ['app', 'binding', 'lwjgl3'].each { module ->
+        ['build', 'sourcesJar', 'javadocJar'].each { task ->
+            t.dependsOn ":imgui-$module:$task"
+        }
+    }
+}