doc-rst: fdl-appendix: Fix formatting issues

doc-rst: fdl-appendix: Fix formatting issues

The conversion didn't add blank lines where needed, but it
added were it weren't ;)

Fix it, to make it to parse correctly by Sphinx. This also
fixes a bunch or warnings:
/devel/v4l/patchwork/Documentation/linux_tv/media/v4l/fdl-appendix:44: WARNING: Explicit markup ends without a blank line; unexpected unindent.
/devel/v4l/patchwork/Documentation/linux_tv/media/v4l/fdl-appendix:52: WARNING: Explicit markup ends without a blank line; unexpected unindent.
/devel/v4l/patchwork/Documentation/linux_tv/media/v4l/fdl-appendix:58: WARNING: Explicit markup ends without a blank line; unexpected unindent.
/devel/v4l/patchwork/Documentation/linux_tv/media/v4l/fdl-appendix:71: WARNING: Explicit markup ends without a blank line; unexpected unindent.
/devel/v4l/patchwork/Documentation/linux_tv/media/v4l/fdl-appendix:78: WARNING: Explicit markup ends without a blank line; unexpected unindent.
/devel/v4l/patchwork/Documentation/linux_tv/media/v4l/fdl-appendix:84: WARNING: Explicit markup ends without a blank line; unexpected unindent.
/devel/v4l/patchwork/Documentation/linux_tv/media/v4l/fdl-appendix:107: WARNING: Explicit markup ends without a blank line; unexpected unindent.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>