A few more notes, like below, might help understand better what this "Include Markdown Reference File" feature really does.
- file format of reference file should be either in Markdown or text file.
- Reference file could contain html tags as well
Or, either of the two below:
1) name this new feature to something like "Include Reference File for HTML output"
2) give more examples to explain the notes above
Since the original name gives the impression that the Reference file must be in markdown format.
BTW, it's great that "experimental settings" now lets translators see and try the new features before actually translating. It helps improving translation greatly