docs: update readme

Author: marcantondahmen

README.md

@@ -1,9 +1,13 @@
 # Revitron Automad Theme
 
-This theme is an [Automad](https://automad.org) port of the [Revitron Sphinx theme](https://github.com/revitron/revitron-sphinx-theme). Check out the Revitron [documentation](https://revitron.readthedocs.io/) as a live demo. Note that this port might differ from the original Sphinx theme in small details.
+This theme is an [Automad](https://automad.org) port of the [Revitron Sphinx theme](https://github.com/revitron/revitron-sphinx-theme). Check out the Revitron [documentation](https://revitron-ui.readthedocs.io/) as a live demo. Note that this port might differ from the original Sphinx theme in small details.
 
 ![](https://raw.githubusercontent.com/marcantondahmen/media-files/master/themes/revitron/default.png)
 
+- [Templates](#templates)
+- [Options](#options)
+- [Custom Color Schemes](#custom-color-schemes)
+
 ## Templates
 
 This theme provides two different templates — a [default](https://revitron.readthedocs.io/en/latest/get-started.html) including a sidebar navigation and a [landing page](https://revitron.readthedocs.io/) template. Content can be added and edited using the block editor. 
@@ -19,6 +23,7 @@ The following variables are available:
 | --- | --- | --- |
 | + Main | The main content block area | Page |
 | Brand | The brand HTML, SVG or text to be used as logo | - |
+| Custom Properties | Custom color definitions to [override](#custom-color-schemes) theme colors | - |
 | Image Logo | The path to your logo - this variable should be defined globally in the shared data section | - |
 | Image Logo Mobile | An alternative logo for smaller devices | - |
 | Items Footer | Additional markup to be added to page's footer | - |
@@ -34,4 +39,13 @@ The following variables are available:
 | Search Results Title | The title for the search results page | Shared |
 | Syntax Theme | The name of the syntax theme for [highlight.js](https://highlightjs.org/static/demo/), the default is 'ascetic'. | Shared |	
 | Url Github | The URL to a related GitHub repository | Shared |
-| Url Pagelist | The URL for the search results page | Shared |
+| Url Pagelist | The URL for the search results page | Shared |
+
+## Custom Color Schemes
+
+The color scheme in this theme is controlled by a set of custom CSS [properties](https://github.com/revitron/revitron-sphinx-theme/blob/master/src/sass/_colors.sass). Therefore it is very easy to override things without actually modifying templates or other files. 
+You can instead add your custom color definitions to the `Custom Properties` field in the **Global Data and Settings** section of the dashboard. For example the background color can be changed by adding the following line to the `Custom Properties` field:
+
+	--bg: hsl(50, 40%, 95%);
+
+A full list of available properties can be found in the [Revitron Sphinx Theme](https://github.com/revitron/revitron-sphinx-theme/blob/master/src/sass/_colors.sass) repository.