Link Gecko and WebKit bugs for ::target-text (#22964)

Author: foolip

css/selectors/target-text.json

@@ -16,7 +16,8 @@
             "chrome_android": "mirror",
             "edge": "mirror",
             "firefox": {
-              "version_added": false
+              "version_added": false,
+              "impl_url": "https://bugzil.la/1694053"
             },
             "firefox_android": "mirror",
             "ie": {
@@ -26,7 +27,8 @@
             "opera": "mirror",
             "opera_android": "mirror",
             "safari": {
-              "version_added": false
+              "version_added": false,
+              "impl_url": "https://webkit.org/b/236817"
             },
             "safari_ios": "mirror",
             "samsunginternet_android": "mirror",