docs-rst: add input docs at main index and use kernel-figure

The input subsystem documentation got converted into ReST.

Add it to the main documentation index and use kernel-figure
for the two svg images there.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/index.rst b/Documentation/index.rst
index 61306a2..bc67dbf 100644
--- a/Documentation/index.rst
+++ b/Documentation/index.rst
@@ -67,6 +67,7 @@
    driver-api/index
    core-api/index
    media/index
+   input/index
    gpu/index
    security/index
    sound/index
diff --git a/Documentation/input/ff.rst b/Documentation/input/ff.rst
index 6a265a6..26d4619 100644
--- a/Documentation/input/ff.rst
+++ b/Documentation/input/ff.rst
@@ -130,11 +130,11 @@
 should also find help in a few sketches, contained in files shape.svg
 and interactive.svg:
 
-.. figure:: shape.svg
+.. kernel-figure:: shape.svg
 
     Shape
 
-.. figure:: interactive.svg
+.. kernel-figure:: interactive.svg
 
     Interactive