update cli docs for process-data (#617)

* update cli docs for process-data

* Update recs

* fix toml

docs/reference/cli/ns_process_data.md

@@ -0,0 +1,14 @@
+# ns-process-data
+
+:::{admonition} Note
+:class: warning
+Make sure to have [COLMAP](https://colmap.github.io) and [FFmpeg](https://ffmpeg.org/download.html) installed.
+:::
+
+```{eval-rst}
+.. argparse::
+    :module: scripts.process_data
+    :func: get_parser_fn
+    :prog: ns-process-data
+    :nodefault:
+```