Implement base system based on internal system with custom template support.

Add a simple post search, similar to filters.

Generate an array with the table of contents data, with levels based on heading and permalinks to each section

Add basic documentation on how to implement a blog and customize it (theming, custom authors, ...).

Add comment, email notification, approve / decline, ban IP, backup + restore, approval form including edit functionality.

Add a simple API to fetch posts for overviews etc.

Add API for general data so that the whole blog area could be an app on the client, getting all data via API (overview, post details, list of authors, ...). Add authentication like usually.

Allow custom image types, like png/webp besides jpg for images, remove hard coded file types from blog engine.

Add an optional API which allows publishing new posts to the blog.

Recommend blog posts of the same category. Feature the latest few ones. If not enough in the current category, simply take the latest few ones, but prevent duplicates and don't feature the current blog post.

Besides the main blog a user should be able to have multiple sections in the app / site where the blog engine can be used (e.g. special areas which are like a blog). Also add the default blog and make an config entry so the user can disable the default blog.

Add default values for all "user:..." config values.

Make it possible to track download counts for special files, like freebies or project zip files.

Easily embed custom plugins / elements in a markdown document, like a poll, specific ads or recommendations, like they are embedded in blog posts on many platforms nowadays to improve content variety and useful stuff like info boxes.