docs: filesystems: convert fuse-io.txt to ReST

- Add a SPDX header;
- Add a document title;
- Add it to filesystems/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/88ec8025c1c5fc3ac5b65f1151c41ebcc696dc0e.1588021877.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/filesystems/fuse-io.txt b/Documentation/filesystems/fuse-io.rst
similarity index 95%
rename from Documentation/filesystems/fuse-io.txt
rename to Documentation/filesystems/fuse-io.rst
index 07b8f73f..255a368 100644
--- a/Documentation/filesystems/fuse-io.txt
+++ b/Documentation/filesystems/fuse-io.rst
@@ -1,3 +1,9 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============
+Fuse I/O Modes
+==============
+
 Fuse supports the following I/O modes:
 
 - direct-io
diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst
index 597ea3e..ace804c 100644
--- a/Documentation/filesystems/index.rst
+++ b/Documentation/filesystems/index.rst
@@ -83,6 +83,7 @@
    hfsplus
    hpfs
    fuse
+   fuse-io
    inotify
    isofs
    nilfs2