esa-snap: add page (#9334)

pages/linux/esa-snap.md

@@ -0,0 +1,12 @@
+# snap
+
+> Sentinel Application Platform (SNAP) for processing satellite data from the European Space Agency (ESA).
+> More information: <http://step.esa.int/main/download/snap-download/>.
+
+- Display all updates:
+
+`snap --nosplash --nogui --modules --list --refresh`
+
+- Display help:
+
+`snap --help`