You no longer have to write raw markdown or BBCode to style text in your posts! We have added the Rich Text Editor extension. It is enabled by default when entering the composer, and can be toggled by clicking the calligraphy pen icon. Using it is hopefully intuitive from the toolbar icons, but if you have any trouble, please do ask. We may write up a guide with screenshots.
Below is an official screenshot showing the various text styling it supports.

We have also added extensions to support markdown tables and checklists, both of which integrate with the Rich Text Editor.