Updated Optional Hardening (markdown)

Optional-Hardening.md

@@ -29,6 +29,23 @@ If the above doesn't work after restarting, then read [here](https://support.moz
 
 ***
 
+### Password, credit card, and address management
+The built-in password manager may be disabled for security.
+
+* `☰` *→ Settings → Privacy & Security → Logins and Passwords → Ask to save logins and passwords for websites*
+
+We recommend using [Bitwarden](https://addons.mozilla.org/en-US/firefox/addon/bitwarden-password-manager/) or [1Password](https://addons.mozilla.org/en-US/firefox/addon/1password-x-password-manager) to manage your credentials on multiple devices.
+```javascript
+// PREF: disable login manager
+user_pref("signon.rememberSignons", false);
+
+// PREF: disable address and credit card manager
+user_pref("extensions.formautofill.addresses.enabled", false);
+user_pref("extensions.formautofill.creditCards.enabled", false);
+```
+
+***
+
 ### Block embedded social posts on webpages
 This matches the default behavior of [Strict](https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop#w_strict-enhanced-tracking-protection) Enhanced Tracking Protection.
 ```javascript