[PATCH v2 4/4] Documentation: input: Document FF_TRIGGER_RUMBLE

[Guillaume Casal]

List the new effect type alongside the others so that userspace
developers can find it when querying device capabilities.

Signed-off-by: Guillaume Casal <guillaume.casal.42@xxxxxxxxx>
---
diff --git a/Documentation/input/ff.rst b/Documentation/input/ff.rst
--- a/Documentation/input/ff.rst
+++ b/Documentation/input/ff.rst
@@ -85,6 +85,7 @@
 - FF_FRICTION	can simulate friction
 - FF_DAMPER	can simulate damper effects
 - FF_RUMBLE	rumble effects
+- FF_TRIGGER_RUMBLE	rumble effects in the triggers
 - FF_INERTIA    can simulate inertia
 - FF_GAIN	gain is adjustable
 - FF_AUTOCENTER	autocenter is adjustable