chore: add snippets of steps for svelte (#2905)

Author: anubra266

website/data/snippets/svelte/steps/installation.mdx

@@ -0,0 +1,5 @@
+```bash
+npm install @zag-js/steps @zag-js/svelte
+# or
+yarn add @zag-js/steps @zag-js/svelte
+```

website/data/snippets/svelte/steps/usage.mdx

@@ -0,0 +1,48 @@
+```svelte
+<script lang="ts">
+  import { normalizeProps, useMachine } from "@zag-js/svelte"
+  import * as steps from "@zag-js/steps"
+
+  const stepsData = [
+    { title: "Step 1" },
+    { title: "Step 2" },
+    { title: "Step 3" },
+  ]
+
+  const service = useMachine(steps.machine, {
+    id: "1",
+    count: stepsData.length,
+  })
+
+  const api = $derived(steps.connect(service, normalizeProps))
+</script>
+
+<div {...api.getRootProps()}>
+  <div {...api.getListProps()}>
+    {#each stepsData as step, index}
+      <div {...api.getItemProps({ index })}>
+        <button {...api.getTriggerProps({ index })}>
+          <div {...api.getIndicatorProps({ index })}>{index + 1}</div>
+          <span>{step.title}</span>
+        </button>
+        <div {...api.getSeparatorProps({ index })} />
+      </div>
+    {/each}
+  </div>
+
+  {#each stepsData as step, index}
+    <div {...api.getContentProps({ index })}>
+      {step.title} - {step.description}
+    </div>
+  {/each}
+
+  <div {...api.getContentProps({ index: stepsData.length })}>
+    Steps Complete - Thank you for filling out the form!
+  </div>
+
+  <div>
+    <button {...api.getPrevTriggerProps()}>Back</button>
+    <button {...api.getNextTriggerProps()}>Next</button>
+  </div>
+</div>
+```