fix: use ui.content instead of ui.description

fix #178

Author: Barbapapazes

src/components/Stepper/Stepper.vue

@@ -147,7 +147,7 @@ defineExpose({
       </RStepperItem>
     </div>
 
-    <div v-if="currentStep?.content || !!slots.content || currentStep?.slot" :class="ui.content({ class: props.ui?.description })">
+    <div v-if="currentStep?.content || !!slots.content || currentStep?.slot" :class="ui.content({ class: props.ui?.content })">
       <slot
         :name="((currentStep?.slot || 'content') as keyof StepperSlots<T>)"
         :item="(currentStep as Extract<T, { slot: string }>)"