doc(typo): change v-id to v-is (#1257)

From https://github.com/vuejs/eslint-plugin-vue/pull/1254/files#diff-86b20cade68a6fa81dfb9c4a6295da05R33

Author: Kocal

docs/rules/no-unsupported-features.md

@@ -30,7 +30,7 @@ The `"ignores"` option accepts an array of the following strings.
   - Vue.js 3.0.0+
     - `"v-model-argument"` ... [argument on `v-model`][Vue RFCs - 0005-replace-v-bind-sync-with-v-model-argument]
     - `"v-model-custom-modifiers"` ... [custom modifiers on `v-model`][Vue RFCs - 0011-v-model-api-change]
-    - `"v-id"` ... [v-is](https://v3.vuejs.org/api/directives.html#v-is) directive.
+    - `"v-is"` ... [v-is](https://v3.vuejs.org/api/directives.html#v-is) directive.
   - Vue.js 2.6.0+
     - `"dynamic-directive-arguments"` ... [dynamic directive arguments](https://v3.vuejs.org/guide/template-syntax.html#dynamic-arguments).
     - `"v-slot"` ... [v-slot](https://v3.vuejs.org/api/directives.html#v-slot) directive.