Added some gradle properties

`net.minecraftforge.gradleutils.ide.automatic.sources`
- Enabled if set to `true`.
- Automatically downloads sources and JavaDocs on IntelliJ IDEA or
Eclipse.

`net.minecraftforge.gradleutils.compilation.defaults`
- Enabled if set to `true`.
- Sets all Java, Groovy, and Javadoc compilation tasks to encode in
UTF-8.
- Sets Groovy compilation tasks to compile with the Indy optimization.
- Sets a human-readable window title for Javadoc and Groovydoc tasks
using either `gradleutils.displayName` or `project.name`.
- Sets the apiNote, implNote, and implSpec tags for Javadoc tasks.
- Emits a warning if there is an enabled Groovydoc task but the default
charset is not UTF-8.
  - It is a Gradle limitation that Groovydoc is invoked via its internal
ant builder rather than in a forked JVM.

Author: Jonathing

src/main/groovy/net/minecraftforge/gradleutils/GradleUtilsExtensionImpl.groovy

@@ -24,11 +24,20 @@ import org.gradle.api.publish.PublishingExtension
 import org.gradle.api.publish.maven.MavenPublication
 import org.gradle.api.publish.maven.tasks.PublishToMavenRepository
 import org.gradle.api.tasks.TaskProvider
+import org.gradle.api.tasks.compile.GroovyCompile
+import org.gradle.api.tasks.compile.JavaCompile
+import org.gradle.api.tasks.javadoc.Groovydoc
+import org.gradle.api.tasks.javadoc.Javadoc
 import org.gradle.authentication.http.BasicAuthentication
+import org.gradle.external.javadoc.StandardJavadocDocletOptions
 import org.gradle.initialization.layout.BuildLayout
+import org.gradle.plugins.ide.eclipse.model.EclipseClasspath
+import org.gradle.plugins.ide.idea.model.IdeaModule
 import org.jetbrains.annotations.Nullable
 
 import javax.inject.Inject
+import java.nio.charset.Charset
+import java.nio.charset.StandardCharsets
 
 import static net.minecraftforge.gradleutils.GradleUtilsPlugin.LOGGER
 
@@ -157,6 +166,41 @@ import static net.minecraftforge.gradleutils.GradleUtilsPlugin.LOGGER
                     it.artifactId = project.extensions.getByType(BasePluginExtension).archivesName
                 }
             }
+
+            if (this.problems.test('net.minecraftforge.gradleutils.ide.automatic.sources')) {
+                project.extensions.findByType(IdeaModule)?.tap { downloadSources = downloadJavadoc = true }
+                project.extensions.findByType(EclipseClasspath)?.tap { downloadSources = downloadJavadoc = true }
+            }
+
+            if (this.problems.test('net.minecraftforge.gradleutils.compilation.defaults')) {
+                project.tasks.withType(JavaCompile).configureEach { task ->
+                    task.options.encoding = 'UTF-8'
+                }
+
+                project.tasks.withType(GroovyCompile).configureEach { task ->
+                    task.options.encoding = 'UTF-8'
+                    task.groovyOptions.optimizationOptions.indy = true
+                }
+
+                final windowTitle = "${this.displayName.orElse(this.project.name).get()} ${this.project.version ?: ''}"
+
+                project.tasks.withType(Javadoc).configureEach { task ->
+                    task.options { StandardJavadocDocletOptions options ->
+                        options.encoding = 'UTF-8'
+                        options.windowTitle = windowTitle
+                        options.tags 'apiNote:a:API Note:', 'implNote:a:Implementation Note:', 'implSpec:a:Implementation Requirements:'
+                    }
+                }
+
+                project.tasks.withType(Groovydoc).configureEach { task ->
+                    task.windowTitle = windowTitle
+
+                    if (task.enabled && Charset.defaultCharset() !== StandardCharsets.UTF_8) {
+                        project.logger.warn('WARNING: Current charset is not UTF-8 but {}! This will affect the output of Groovydoc task {}', Charset.defaultCharset(), task.name)
+                        this.problems.reportGroovydocIncorrectCharset(task)
+                    }
+                }
+            }
         }
 
         @Override

src/main/groovy/net/minecraftforge/gradleutils/GradleUtilsProblems.java

@@ -6,9 +6,11 @@
 
 import net.minecraftforge.gradleutils.shared.EnhancedProblems;
 import org.gradle.api.problems.Severity;
+import org.gradle.api.tasks.javadoc.Groovydoc;
 
 import javax.inject.Inject;
 import java.io.Serial;
+import java.nio.charset.Charset;
 
 abstract class GradleUtilsProblems extends EnhancedProblems {
     private static final @Serial long serialVersionUID = 3278085642147772954L;
@@ -63,4 +65,18 @@ This can be done by declaring it as so (in Groovy DSL):
             .solution(HELP_MESSAGE));
     }
     //endregion
+
+    //region
+    void reportGroovydocIncorrectCharset(Groovydoc task) {
+        this.getReporter().report(id("groovydoc-incorrect-charset", "Groovydoc charset is incorrect"), spec -> spec
+            .details("""
+                Groovydoc tasks cannot have their charsets manually set, and your default charset is not UTF-8.
+                This may cause problems in the output of your Groovydoc.
+                Affected task: %s
+                Current charset: %s""".formatted(task.getName(), Charset.defaultCharset()))
+            .severity(Severity.WARNING)
+            .stackLocation()
+            .solution("Set the JVM's default charset to UTF-8 using `propName.file.encoding=UTF-8` in your gradle.properties."));
+    }
+    //endregion
 }