[rurban]

This is a bit incorrect.

"La Sortie des ouvriers de l’usine Lumière" was their first documentary they projected in Lyon publicly. But already a few years ago, 1893, the Edison Kinetoscope was used to produce the first short films, viewable only through a peephole. Several other such apparatus existed in Europe before the Lumiere's. The Kinetoscope was a huge success, Lumiere's projectors also.

The train arriving in La Ciotat was a bigger production, because they had to travel some hours to the south, and was something they wanted to present in Paris. But I would count the Blacksmiths or Fred Ott's Sneeze more of a movie than the first Lumiere docs. And they are much earlier.

Eg https://en.wikipedia.org/wiki/Kinetoscope