Lack of documentation for deepFreezeFn

[piotrgredowski]

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[ ] Bug report  
[ ] Performance issue
[ ] Feature request
[x] Documentation issue or request
[ ] Support request
[ ] Other... Please describe:

Current behavior

Docstring of deepFreezeFn doesn't contain any valuable information - only function definition function customDeepFreeze(state) { return freezedState; }. Should it be like that?

Expected behavior

More explanation of how deepFreezeFn can be used.

Minimal reproduction of the problem with instructions

For bug reports please provide the STEPS TO REPRODUCE and if possible a MINIMAL DEMO of the problem via
https://stackblitz.com or similar (you can use this template as a starting point: https://stackblitz.com/github/NetanelBasal/akita-issue-seed).

What is the motivation / use case for changing the behavior?

Better documentation :)

Environment

Angular version: X.Y.Z


Browser:
- [x] Chrome (desktop) version XX
- [x] Chrome (Android) version XX
- [x] Chrome (iOS) version XX
- [x] Firefox version XX
- [x] Safari (desktop) version XX
- [x] Safari (iOS) version XX
- [x] IE version XX
- [x] Edge version XX
 
For Tooling issues:
- Node version: XX  
- Platform:  

Others:

[NetanelBasal]

What is missing? You get the state, and you need to return a frozen version of it.