Remove PayPal from the installation instructions

It's no longer an option in the script

See solidusio/solidus#4494

docs/getting-started/installing-solidus.mdx

@@ -67,15 +67,12 @@ $ bundle add 'solidus'
 $ bin/rails generate solidus:install
 ```
 
-The installer will prompt you on a few questions before completing the installation. First it will
-ask if you would like to use the default authentication
-solution, [Devise](https://github.com/heartcombo/devise), or your implement your own. Next it will
-ask what payment service you would like to install with solidus.Currently, Solidus comes packaged
-with [Paypal](https://developer.paypal.com/home) as the default and only option. Other integrated
-services that you tie into your application can be found and in the payment section
-of [Solidus extensions](https://solidus.io/extensions/). If you want to skip installing a payment
-service, just type 'none'. Finally, you will be prompted for an admin email and password. You can
-leave the default (email: [email protected], password: test123) or enter your own.
+The installer will prompt you on a few questions before completing the
+installation. It will ask if you would like to use the default authentication
+solution, [Devise](https://github.com/heartcombo/devise), or your implement
+your own. Finally, you will be prompted for an admin email and password. You
+can leave the default (email: [email protected], password: test123) or enter
+your own.
 
 Once the installation has completed, you can now start your Rails server: