add datalad run command for dataset_description.json to docs

code/docs/highspeed-bids-docs.Rmd

@@ -200,6 +200,10 @@ Python 3.8.5
 
 `highspeed-bids-description.py` is a short Python script that loads the `dataset_description.json` file that is pre-generated by HeuDiConv and populates it with the relevant study informtion.
 
+```bash
+datalad run -m "create dataset_description.json" --output "dataset_description.json" "python3 code/bids_conversion/highspeed-bids-description.py"
+```
+
 ```{python, echo=TRUE, code=readLines(file.path(path_root, "code", "bids_conversion", "highspeed-bids-description.py")), eval=FALSE, python.reticulate=FALSE}
 ```