chore(REUSE): add /css

Signed-off-by: Grigorii K. Shartsev <me@shgk.me>

REUSE.toml

@@ -11,6 +11,12 @@ precedence = "aggregate"
 SPDX-FileCopyrightText = "2016 Nextcloud GmbH and Nextcloud and ownCloud contributors"
 SPDX-License-Identifier = "AGPL-3.0-or-later"
 
+[[annotations]]
+path = ["css/**.css", "css/**.css.map"]
+precedence = "aggregate"
+SPDX-FileCopyrightText = "2016 Nextcloud GmbH and Nextcloud contributors"
+SPDX-License-Identifier = "AGPL-3.0-or-later"
+
 [[annotations]]
 path = ["js/**.mjs", "js/**.mjs.map"]
 precedence = "aggregate"