Add new "post-content-preview" component

This part defined in the "tag" component would be useful as a standalone component: https://gitlab.syncad.com/hive/web-components/-/blob/develop/packages/component-tag/src/hive-tag.ts?ref_type=heads#L360

<div class="post-content">
  <img class="preview-img" src="${imageUrl}" alt="Post image" loading="lazy" />
  <div class="post-excerpt">
    <h2 class="post-title">${post.title}</h>
    <p class="post-preview" .innerHTML=${preview}></p>
  </div>
</div>