Add jgvariant-ostree module.

Change-Id: Idf7bacad28d7cf65eb1ddd0994dcc2c2c2a7e18e
diff --git a/jgvariant-ostree/src/main/java/module-info.java b/jgvariant-ostree/src/main/java/module-info.java
new file mode 100644
index 0000000..e51c586
--- /dev/null
+++ b/jgvariant-ostree/src/main/java/module-info.java
@@ -0,0 +1,85 @@
+/**
+ * Provides a parser for the <a href="https://docs.gtk.org/glib/struct.Variant.html">GVariant</a>
+ * serialization format.
+ *
+ * <ul>
+ *   <li><a href="#sect-overview">Overview</a>
+ *   <li><a href="#sect-installation">Installation</a>
+ * </ul>
+ *
+ * <h2 id="sect-overview">Overview</h2>
+ *
+ * <p>The {@link eu.mulk.jgvariant.ostree} package contains record classes describing the elements
+ * of <a href="https://ostreedev.github.io/ostree/">OSTree</a> repositories and factory methods to
+ * create {@link eu.mulk.jgvariant.core.Decoder} instances for them.
+ *
+ * <h2 id="sect-installation">Installation</h2>
+ *
+ * <ul>
+ *   <li><a href="#sect-installation-maven">Usage with Maven</a>
+ *   <li><a href="#sect-installation-gradle">Usage with Gradle</a>
+ * </ul>
+ *
+ * <h3 id="sect-installation-maven">Usage with Maven</h3>
+ *
+ * <pre>{@code
+ * <project>
+ *   ...
+ *
+ *   <dependencyManagement>
+ *     ...
+ *
+ *     <dependencies>
+ *       <dependency>
+ *         <groupId>eu.mulk.jgvariant</groupId>
+ *         <artifactId>jgvariant-bom</artifactId>
+ *         <version>0.1.4</version>
+ *         <type>pom</type>
+ *         <scope>import</scope>
+ *       </dependency>
+ *     </dependencies>
+ *
+ *     ...
+ *   </dependencyManagement>
+ *
+ *   <dependencies>
+ *     ...
+ *
+ *     <dependency>
+ *       <groupId>eu.mulk.jgvariant</groupId>
+ *       <artifactId>jgvariant-core</artifactId>
+ *     </dependency>
+ *     <dependency>
+ *       <groupId>eu.mulk.jgvariant</groupId>
+ *       <artifactId>jgvariant-ostree</artifactId>
+ *     </dependency>
+ *
+ *     ...
+ *   </dependencies>
+ *
+ *   ...
+ * </project>
+ * }</pre>
+ *
+ * <h3 id="sect-installation-gradle">Usage with Gradle</h3>
+ *
+ * <pre>{@code
+ * dependencies {
+ *   ...
+ *
+ *   implementation(platform("eu.mulk.jgvariant:jgvariant-bom:0.1.4")
+ *   implementation("eu.mulk.jgvariant:jgvariant-core")
+ *   implementation("eu.mulk.jgvariant:jgvariant-ostree")
+ *
+ *   ...
+ * }
+ * }</pre>
+ */
+module eu.mulk.jgvariant.gvariant {
+  requires transitive eu.mulk.jgvariant.core;
+  requires com.google.errorprone.annotations;
+  requires org.jetbrains.annotations;
+  requires org.apiguardian.api;
+
+  exports eu.mulk.jgvariant.ostree;
+}