Filled demo added

doc/checkbox/FilledDoc.vue

@@ -0,0 +1,54 @@
+<template>
+    <DocSectionText v-bind="$attrs">
+        <p>Specify the <i>variant</i> property as <i>filled</i> to display the component with a higher visual emphasis than the default <i>outlined</i> style.</p>
+    </DocSectionText>
+    <div class="card flex justify-content-center">
+        <Checkbox v-model="checked" binary variant="filled" />
+    </div>
+    <DocSectionCode :code="code" />
+</template>
+
+<script>
+export default {
+    data() {
+        return {
+            checked: false,
+            code: {
+                basic: `
+<Checkbox v-model="checked" binary variant="filled" />
+`,
+                options: `
+<template>
+    <div class="card flex justify-content-center">
+        <Checkbox v-model="checked" binary variant="filled" />
+    </div>
+</template>
+
+<script>
+export default {
+    data() {
+        return {
+            checked: false
+        };
+    }
+};
+<\/script>
+`,
+                composition: `
+<template>
+    <div class="card flex justify-content-center">
+        <Checkbox v-model="checked" binary variant="filled" />
+    </div>
+</template>
+
+<script setup>
+import { ref } from "vue";
+
+const checked = ref(false);
+<\/script>
+`
+            }
+        };
+    }
+};
+</script>