Make stronger accent that the front end application needs to be "Web app"

[adriatic]

The title of this issue should be used in the context of the Express & Okta-Hosted Login Page Example.

The Prerequisites section states:

Before running this sample, you will need the following:

• An Okta Developer Account, you can sign up for one at https://developer.okta.com/signup/.
• An Okta Application, configured for Web mode. This is done from the Okta Developer Console and you can find instructions here. When following the wizard, use the default properties. They are designed to work with our sample applications.

Note the boldfaced text An Okta Application, configured for Web mode. Despite seeing this, I was happily able to glance over that and happily used the application configured as SPA instead. The obvious problem with this is that I could not find the Client Secret for this SPA app -- and spent hours searching through all docs for information where to find it.

Perhaps the Client Credentials section should look like this (in the case of a SPA app):