changed license to CC-BY-SA-4.0, wrote some readme contents

README.md

@@ -1 +1,22 @@
 # KiCad Library for Visaton Germany
+
+This KiCad library contains the electronics components to build crossovers for Speakerboxes of the german vendor Visaton. It includes the symbols. footprints and 3D models.
+
+## Installation
+
+### Clone the repository
+
+Clone this repository to a preferred place on your harddisk and impirt the symbols and footprints using the library managers. 
+
+### Download as ZIP
+
+Download the packae as ZIP-File and install it using the KiCad AddOn manager. 
+
+## Known issues
+
+* The positions of the footsprints of the inductors might not really fit the original positions. I couldn't find reliable geometrics.
+
+* The pads are connected to both copper layers. They should only connectvthe back copper layer, because crossovers are single layered most of the time.
+
+* The geometry of some symbols, especially the capacitors, are a little to huge.
+