doc: cmd: Add documentation for fuse command

Add documentation for the 'fuse' sub-system commands in
doc/usage/cmd/fuse.rst file.
Remove doc/README.fuse file.

Signed-off-by: Harsha Vardhan V M <h-vm@ti.com>
diff --git a/doc/usage/index.rst b/doc/usage/index.rst
index fc05847..372ef56 100644
--- a/doc/usage/index.rst
+++ b/doc/usage/index.rst
@@ -72,6 +72,7 @@
    cmd/fdt
    cmd/font
    cmd/for
+   cmd/fuse
    cmd/fwu_mdata
    cmd/gpio
    cmd/gpt