doc: fix sphinx compatibility
authorThomas Monjalon <thomas@monjalon.net>
Wed, 8 Apr 2020 08:09:23 +0000 (10:09 +0200)
committerThomas Monjalon <thomas@monjalon.net>
Wed, 15 Apr 2020 13:21:06 +0000 (15:21 +0200)
commit10d34aa3dee8daf0a07ae152de8377942f63503b
treefde5e2d050be9cb79978027d8e79b17c360917be
parentf34cb24522890a49fa8bbda3ec334f4df27df823
doc: fix sphinx compatibility

The function add_stylesheet() is deprecated since sphinx 1.8.
It will be removed in sphinx 4.0.
It is replaced by add_css_file().

Cc: stable@dpdk.org
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
doc/guides/conf.py