Remove extra line to fix formatting

The formatting of the 'cd_content' is broken on the website - it looks like the extra blank line between the two paragraphs combined with the four spaces preceding the "-" make the '.mdx' interperter see the block as code and not MarkDown coded text.

docs/builders/iso.mdx

@@ -355,7 +355,6 @@ or responding to pattern `/dev/.+`. Example:
         * hdiutil (normally found in macOS)
         * oscdimg (normally found in Windows as part of the Windows ADK)
 
-
     - `cd_content` (map[string]string) - Key/Values to add to the CD. The keys represent the paths, and the values
       contents. It can be used alongside `cd_files`, which is useful to add large
       files without loading them into memory. If any paths are specified by both,