Re-rendering only modified components

### Issue type

I don't know if this is specific to ngx-admin specifically, but it stands out mostly in the ngx-admin project.

Is there a way to prevent a full page refresh when developing? For example, if I change the header component ONLY, the whole page is re-rendered again.

I would expect that a component can be hot-reloaded without having to re-render all the components. I come from a Vue background, and one the things that made for speedy development was the hot-reloading of components.

Is this an Angular limitation? Configuration issue?

Thanks

* [x] bug report
* [ ] feature request
* [x] question about the decisions made in the repository

### Issue description

**Current behavior:**
Any change in any component causes a full page re-render.

**Expected behavior:**
I would like only the changed component to re-render

**Steps to reproduce:**
1. Run in dev server
2. Modify a component

**Related code:**
N/A