refactor: firefox: move security.ssl.require_safe_negotiation docs to user.js

hosts/common/programs/firefox/default.nix

@@ -1,6 +1,3 @@
-# common settings to toggle (at runtime, in about:config):
-#   > security.ssl.require_safe_negotiation
-
 { config, lib, pkgs, ...}:
 let
   cfg = config.sane.programs.firefox.config;

hosts/common/programs/firefox/user.js

@@ -15,6 +15,9 @@
 // - number
 // anything else (e.g. arrays, objects) MUST be represented as strings (use backticks for multiline/raw strings)
 
+// COMMON SETTINGS TO TOGGLE (at runtime, in about:config)
+// defaultPref("security.ssl.require_safe_negotiation", false);
+
 ///// RESET UNWANTED ARKENFOX CHANGES
 // browser.sessionstore.privacy_level: 0, 1, 2
 // 0: persist partially-filled forms to disk, across browser restarts