Migration from VuePress 
Config 
Sidebar 
The sidebar is no longer automatically populated from frontmatter. You can read the frontmatter yourself to dynamically populate the sidebar. Additional utilities for this may be provided in the future.
Markdown 
Images 
Unlike VuePress, VitePress handles base of your config automatically when you use static image.
Hence, now you can render images without img tag.
diff
- <img :src="$withBase('/foo.png')" alt="foo">
+ WARNING
For dynamic images you still need withBase as shown in Base URL guide.
Use <img.*withBase\('(.*)'\).*alt="([^"]*)".*> regex to find and replace it with  to replace all the images with  syntax.
more to follow...