The note taking and personal knowledge management tool Obsidian has a community plugin, that allows publishing of Obsidian notes to WordPress.
It does not however support updating an Obsidian note from a changed WordPress post. It does not yet do pages, inline images or custom fields. But it seems the developer Cheng Liang is working on improving it. Unfortunatly the last update appears to be almost half a year ago.
Here is the GitHub repository for that extension: https://github.com/devbean/obsidian-wordpress