feat: add v-if documentation for Vue.js (#6415)

* feat: add v-if documentation for Vue.js

* Update src/data/roadmaps/vue/content/v-if@xHj3W9Ig3MVuVlGyXchaP.md

---------

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

src/data/roadmaps/vue/content/v-if@xHj3W9Ig3MVuVlGyXchaP.md

@@ -1 +1,9 @@
-# v-if
+# v-if
+
+Conditionally render an element or a template fragment based on the truthy-ness of the expression value.
+
+When a `v-if` element is toggled, the element and its contained directives / components are destroyed and re-constructed. If the initial condition is falsy, then the inner content won't be rendered at all.
+
+Visit the following resources to learn more:
+
+- [@official@v-if Documentation](https://vuejs.org/api/built-in-directives.html#v-if)