Add support for stripping all tags

[zcolleyz]

This PR adds the ability to render HTML entities without any HTML:

<template>
  <div v-safe-html:strip-tags="'<p><strong>Cats<strong> &amp; <em>&quot;Dogs&quot;</em></p>'" />
</template>

Renders to:

<div>Cats &amp; "Dogs"</div>

This behaviour will ignore any modifiers.

• Create a strip-tags argument that strips all tags
• Bump version to 2.3.0
• Update documentation

[zcolleyz]

We have no current need for this feature any more. If someone finds this you can either use the allowedTags option or restart the conversation for this feature and we'll go from there.