I found myself wanting a quick way to add simple titles to lots of images. Rather than writing a separate script I thought that just adding a new command to sigal itself might be easier. Do you think this is worth including in upstream sigal? In that case I can add test cases and documentation for it, but wanted to see if you'd want to take it at all first...
This can set an arbitrary number of meta keys and also supports creating meta files for directories (i.e. index.md files). Signed-off-by: Toke Høiland-Jørgensen <email@example.com>