docs: update example app

[timdeschryver]

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[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
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Would it be OK to update the example app deployed on GitHub?

Things I've changed to make it imho easier for users taking a look:

• enable actions in the devtools
• also enable login with ngrx, which is also prefilled in the username textbox

We could also make these changes on the master branch?

I didn't update the StackBlitz example, because it can't handle the aliased paths defined in tsconfig.app.json.

Related: this is in order to update the NgRx documentation for the Redux Dev Tools extension, which were based on NgRx version 2 - zalmoxisus/redux-devtools-extension#623

[brandonroberts]

What changes were made to the actual example app for this?

[timdeschryver]

Removed log only - this to play around with the extension, plus zalmoxisus/redux-devtools-extension#623 (comment)

Allow ngrx as username, to make it more pleasing:

Defaulted to ngrx as username, to make it easier to login without the need to take a look at the source code:

[timdeschryver]

If you would rather not update the example app or to deploy it without the changes, that's fine by me too 😄

[brandonroberts]

Deploying without updating is fine if these changes are temporary.