docs: fix: zipPattern escape \

Author: shinokada

src/routes/docs/forms/number-input.md

@@ -38,6 +38,7 @@ Use this example with an icon and helper text to set a ZIP code value inside a f
 <script lang="ts">
   import { Input, Label, P } from "flowbite-svelte";
   import { MapPinAltSolid } from "flowbite-svelte-icons";
+  const zipPattern = "^\\d{5}(-\\d{4})?$";
 </script>
 
 <form class="max-w-sm mx-auto">
@@ -46,7 +47,7 @@ Use this example with an icon and helper text to set a ZIP code value inside a f
         <div class="absolute inset-y-0 start-0 top-0 flex items-center ps-3.5 pointer-events-none">
             <MapPinAltSolid />
         </div>
-        <Input type="text" pattern="^\d{5}(-\d{4})?$" title="Enter ZIP code: 12345 or 12345-6789" inputmode="numeric" placeholder="12345 or 12345-6789" class="ps-10" aria-describedby="helper-text-explanation" required />
+        <Input type="text" pattern={zipPattern} title="Enter ZIP code: 12345 or 12345-6789" inputmode="numeric" placeholder="12345 or 12345-6789" class="ps-10" aria-describedby="helper-text-explanation" required />
     </div>
     <P id="helper-text-explanation" class="mt-2 text-sm" >Enter either a standard 5-digit ZIP code or the extended ZIP+4.</P>
 </form>