@astrojs/markdown-remark@6.0.1

#12646 f13417b Thanks @bluwy! - Avoids parsing frontmatter that are not at the top of a file
#12570 87231b1 Thanks @GrimLink! - Removes trailing new line in code blocks to prevent generating a trailing empty <span /> tag
#12664 a71e9b9 Thanks @bluwy! - Fixes frontmatter parsing if file is encoded in UTF8 with BOM