docs: update README

Author: json-derulo

README.md

@@ -14,16 +14,7 @@ You want to style your angular material dynamically with all the colors in the r
     ```scss
     @use 'angular-material-css-vars' as mat-css-vars;
  
-    // init theme
-    @include mat-css-vars.init-material-css-vars(
-      // optional
-      $dark-theme-selector: '.isDarkTheme',
-      $light-theme-selector: '.isLightTheme',
-   ) using($mat-css-theme) {
-      // If your app has any theme mixins, call them here. 
-      // $mat-css-theme gets set to an appropriate value before this content is called.
-      // @include your-custom-component-theme($mat-css-theme);
-    };
+    @include mat-css-vars.init-material-css-vars();
     ```
 4. Add to your main module:
 ```typescript
@@ -34,16 +25,15 @@ import {MaterialCssVarsModule} from 'angular-material-css-vars';
     MaterialCssVarsModule.forRoot({
       // all optional
       isAutoContrast: true,
-      darkThemeClass: 'isDarkTheme',
-      lightThemeClass: 'isLightTheme',
+      primary: '#3f51b5',
       // ...
     }),
   ],
 })
 export class AppModule {
 }
 ```
-5. Then use it like so:
+5. If you want to adjust the theme at runtime, you can use `MaterialCssVarsService`:
     ```typescript
     import {MaterialCssVarsService} from 'angular-material-css-vars';
     
@@ -90,36 +80,15 @@ There are also [some additional hacks](additional-hacks.md) (e.g. adding a color
 You can provide different options before initialization to change the body class used for the dark theme and to provide different default styles:
 ```scss
 ...
-@use 'angular-material-css-vars' as mat-css-vars;
-...
-
-@include mat-css-vars.init-material-css-vars(
-  // $default-light-theme: ... ;
-  // $text: ... ;
+@use 'angular-material-css-vars' as mat-css-vars with (
   $dark-theme-selector: '.isDarkTheme',
-  $light-theme-selector: '.isLightTheme',
+  $light-theme-selector: '.isLightTheme'
 );
+...
 
-``` 
-To make those variables take effect with your mixins, you need to make sure that they are also defined before using them. E.g.:
-```scss
-@use 'angular-material-css-vars' as mat-css-vars;
-
-@include mat-css-vars.init-material-css-vars(
-  // probably best put in a common variables file and imported before the mixins
-  $dark-theme-selector: '.isDarkTheme',
-);
+@include mat-css-vars.init-material-css-vars();
 
-.my-component {
-  @include mat-css-vars.mat-css-dark-theme {
-    // dark theme styles ...  
-  } 
-}
 ```
- 
-
-A full list of the theme map [can be found here](https://github.com/johannesjo/angular-material-css-vars/blob/master/projects/material-css-vars/src/lib/_variables.scss).
-
 
 ### Set default (fallback palettes)
 There are two ways to set the default fallback theme. One is using the `mat-css-palette-defaults` mixin.
@@ -133,14 +102,10 @@ There are two ways to set the default fallback theme. One is using the `mat-css-
 @include mat-css-vars.mat-css-set-palette-defaults(mat.$pink-palette, 'accent');
 @include mat-css-vars.mat-css-set-palette-defaults(mat.$red-palette, 'warn');
 ```
-The other is to include your own variables for [$mat-css-default-light-theme](https://github.com/johannesjo/angular-material-css-vars/blob/master/projects/material-css-vars/src/lib/_variables.scss).
+The other is to include your own variables for [$default-light-theme](https://github.com/johannesjo/angular-material-css-vars/blob/master/projects/material-css-vars/src/lib/_variables.scss).
 ```scss
-@use 'angular-material-css-vars' as mat-css-vars;
-
-$mat-css-default-light-theme: map-merge(
-  // if you don't want to enter ALL the properties
-  mat-css-vars.$default-light-theme,
-  (
+@use 'angular-material-css-vars' as mat-css-vars with (
+  $default-light-theme: (
     --palette-primary-50: mat-css-vars.hex-to-rgb(#e1f5fe),
     --palette-primary-100: mat-css-vars.hex-to-rgb(#b3e5fc),
     --palette-primary-200: mat-css-vars.hex-to-rgb(#81d4fa),