What problem does this feature solve?

excluding pages via filter function and/or exclude globs is fine for a global configuration.

That being said, sometimes we would like the configuration to be related to the page itself (i.e a terms & conditions page that is duplicated across projects).

What does the proposed changes look like?

Terms.vue

<template>
...
</template>
<script>
export default {
      sitemap:false
}
</script>
<style>
...
</style>

A pull request is available in #70