Added input defaults and automatic build on pre-commit

[samueljim]

@jamesrplee The main.ts file now defines a set of default values that will be used when an input is missing.
This means that if the input isn't passed in then the value here will be used.

For example, this request is saying to hide logos but it will use the default title as there is no value passed in. The way there is no undefined string printed as there is always a fallback value.
https://cdn.make.cm/make/t/439a758e-3335-48b3-a923-c8ffccb702c4/k/6f1e51fd-dac7-468a-b73c-33092bfc0150.a797e51d472c0d6c32517d5edb7f2907/sync?size=A4&format=pdf&data[showLogos]=false

[samueljim]

I can make the same automatic build and default value change for the other example repos if you think this is a good change

[jamesrplee]

A few questions in there @samueljim.

The bigger question I have is, whether we want default values at all in the boilerplate? Or whether we just run a conditon on the inputs that if null we remove the element. For these templates that would make more sense.

Another option is we leave them in there but comment them out so that the end user can decide whether to use them or not. I just don't want to devs to feel like they have to use default values if the API returns null.

What do you think?

[jamesrplee]

Do we need pre-commit as a dependency? What's it offering for the boilerplate?

[jamesrplee]

Defining an object and then instantly spreading it seems a bit dank. Couldn't we just do?

const props = {
  foo: 'bar',
   ...window.templateProps
}