Simplified command-line argument to generate JSON

[rwatson]

I suspect there are lots of magic libxo arguments I can use, once I figure them out, but it would be useful to also add a -j argument to force JSON output to avoid the need to read the libxo(3) man page in detail for basic use. In the L41 labs, I use this code when spotting the -j:

xo_set_style(NULL, XO_STYLE_JSON);
xo_set_flags(NULL, XOF_PRETTY);

Which seems to do the trick.

[psjm3]

I have added the changes to include a -j option, but the output doesn't run until the end, almost like some kind of buffer has run out. But even if I pipe the output to more or to a file, it only goes so far and the rest of the output is cut off.

This branch has the changes: https://github.com/CTSRD-CHERI/chericat/tree/add-json-option