feat: allow/describe how to define custom styles

closes #121

README.md

@@ -30,7 +30,7 @@ Generate the `rd.json` file containing the radar data
 npx aoe_technology_radar-generateJson
 ```
 
-Run the Prepare script 
+Run the Prepare script
 ```
 npm run prepare
 ```
@@ -207,6 +207,25 @@ Create a `fonts.css` in the public folder and load your fonts.
 
 For reference have a look at [public/fonts.css](./public/fonts.css).
 
+### Change the styles
+
+To change the styles, create a `styles.css` in the `public` folder and apply your style modifications.
+Styles defined in `public/styles.css` will overload the default styles.
+
+For reference have a look at [src/styles/main.scss](./src/styles/main.scss) and all it's included files.
+
+> Important: The custom styles must be defined as pure CSS,
+> as there is no further pre-processing of other file formats such as SCSS for custom style overloads.
+
+You can also reference custom icons or images in your styles as follows.
+The icons should be placed in the `public` folder as well (e.g. in a specific `icons` or `images` directory):
+
+```css
+body {
+  background-image: url('/images/my-custom-background-image.png');
+}
+```
+
 ### Add social links to the footer and sidebar
 To add social links, create a public folder in your application and put a `messages.json` in it.
 ```json

public/index.html

@@ -8,6 +8,7 @@
   <meta name="description" content="%REACT_APP_RADAR_NAME%" />
   <link rel="apple-touch-icon" href="%PUBLIC_URL%/logo.svg" />
   <link rel="stylesheet" href="%PUBLIC_URL%/fonts.css">
+  <link rel="stylesheet" href="%PUBLIC_URL%/styles.css">
   <meta property="og:title" content="%REACT_APP_RADAR_NAME%" />
   <meta property="og:image" content="%PUBLIC_URL%/logo.svg" />
 

public/styles.css

@@ -0,0 +1,3 @@
+/*
+ * Define your custom CSS Styles here.
+ */