docs: update theme

Author: mrholek

packages/docs/.vuepress/theme-coreui/src/client/components/Sidebar.vue

@@ -17,7 +17,7 @@
         </g>
       </svg>
     </CSidebarBrand>
-    <div class="text-body-secondary ms-3 me-5 mb-2 small fw-semibold">Framework:</div>
+    <div class="text-muted ms-3 me-5 mb-2 small fw-semibold">Framework:</div>
     <CDropdown class="ms-3 me-5 mb-4">
       <CDropdownToggle color="primary" variant="outline"> Vue.js </CDropdownToggle>
       <CDropdownMenu class="w-100">