fix: svg icon issues with fill (#267)

* refactor: simplified icon filled declarations

* refactor: simplified the logos fill styles as well

* docs: adapted instructions to README

* chore: added another necessary replaced color

assets/icons/README.md

@@ -4,6 +4,10 @@ We're getting these icons by the [DB Design System colleagues](https://dbsw.shar
 
 - Minifications with [`ImageOptim`](https://imageoptim.com/mac)
 - Adding some contents within the SVGs (these assets might get exported correctly in the future)
-  - CSS variables (replace `fill="#282D37"` by `fill="#282D37" style="fill: currentColor;fill: var(--db-icon-color, currentColor)"`)
+  - CSS variables
+    - replace `fill="#282D37"` by `fill="var(--db-icon-color, currentColor)"`
+    - replace `fill="#55b9e6"` by `fill="var(--db-icon-color, #55b9e6)"`
+    - replace `fill="#EC0016"` by `fill="var(--db-icon-pulse-color, #EC0016)"`
+    - replace `fill="#78be14"` by `fill="var(--db-icon-pulse-color, #78be14)"`
   - `id`-Attribute (generic `icon` id within all SVG files)
 - Afterwards the JSON files within the `source/_patterns/icons` path might need to get updated