man: Add missing command line options

These options were documented in --help but missing from the man page.

Signed-off-by: Keith Packard <keithp@keithp.com>

Author: keith-packard

man/man1/cmark-gfm.1

@@ -66,6 +66,18 @@ URLs are those that begin with `javascript:`, `vbscript:`,
 `file:`, or `data:` (except for `image/png`, `image/gif`,
 `image/jpeg`, or `image/webp` mime types).
 .TP 12n
+.B \-\-github-pre-lang
+Use GitHub-style <pre lang> for code blocks.
+.TP 12n
+.B \-\-strikethrough-double-tilde
+Only parse strikethrough (if enabled) with two tildes.
+.TP 12n
+.B \-\-table-prefer-style-attributes
+Use style attributes to align table cells instead of align attributes.
+.TP 12n
+.B \-\-full-info-string
+Include remainder of code block info string in a separate attribute.
+.TP 12n
 .B \-\-help
 Print usage information.
 .TP 12n