add creating-a-storage.md

docs/storage/getting-started/creating-a-storage.md

@@ -0,0 +1,27 @@
+# Creating a custom Storage
+
+Creating a custom Storage is fairly simple. All you need is to create a class that extends the `Storage` class and
+implement the required methods.
+```java
+public static class ExampleStorage extends Storage {
+    private int exampleInt = 0;
+
+    public ExampleStorage(StorageHolder holder) {
+        super(holder);
+    }
+
+    @Override
+    public void save(CompoundTag data) {
+        data.putInt("exampleInt", exampleInt);
+    }
+
+    @Override
+    public void load(CompoundTag data) {
+        exampleInt = data.getInt("exampleInt");
+    }
+
+    public int getExampleInt() {
+        return exampleInt;
+    }
+}
+```