doc: note about firefox share compatibility

diff --git a/doc/md/Firefox-share.md b/doc/md/Firefox-share.md
index 878884a497e9bc67879576db27ff0216cd2a24ba..9a46b1854c401dc736fba9495ea12b214a79c08d 100644 (file)
--- a/doc/md/Firefox-share.md
+++ b/doc/md/Firefox-share.md
@@ -1,3 +1,6 @@
+| Note | Firefox Share is no longer available for Firefox 57 and later versions. |
+|---------|---------|
+
 ### Add Shaarli as a sharing service to Firefox
 
 - Open your Shaarli and `Login`