Added GUEST_PASSWORD to README (#80)

* Added GUEST_PASSWORD to README

* comment out and reject default value

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Co-authored-by: Wingy <git@wingysam.xyz>

README.md

@@ -93,6 +93,9 @@ UPDATE_CHECK=true
 PFP=true
 # Language of the interface, options listed in `languages` directory
 LANGUAGE=en-US
+# Password to enter guest mode,
+# e.g. https://wishes.example.com?pw=ReplaceWithYourGuestPassword
+# GUEST_PASSWORD=ReplaceWithYourGuestPassword
 
 ## Wishlist Settings
 # Set to true to not allow users to have their own lists. You may want this for a birthday or wedding.
@@ -144,4 +147,4 @@ As of writing, there are no code contributors to the main project. However, ther
 * Czech: [drSchaps](https://github.com/drSchaps)
 * German: [PeteS4](https://github.com/PeteS4)
 * French: [zethis](https://github.com/zethis)
-* Spanish: [CantisW](https://github.com/CantisW)
+* Spanish: [CantisW](https://github.com/CantisW)

src/config/index.js

@@ -25,3 +25,7 @@ module.exports = {
 }
 
 if (module.exports.guestPassword) module.exports.wishlist.public = false
+if (module.exports.guestPassword === 'ReplaceWithYourGuestPassword') {
+  console.error('Error: Guest password should be changed from default.')
+  process.exit(1)
+}