Network map fix Css/img (#12498)

* Add files via upload

* Delete zoomExtends.png

* Delete upArrow.png

* Delete minus.png

* Delete plus.png

* Delete leftArrow.png

* Delete downArrow.png

* Delete rightArrow.png

* Create test

* Add files via upload

* Create readme

* Add files via upload

* Delete downArrow.png

* Delete leftArrow.png

* Delete minus.png

* Delete plus.png

* Delete rightArrow.png

* Delete test

* Delete upArrow.png

* Delete zoomExtends.png

* Update readme

html/css/img/network/readme

@@ -0,0 +1,2 @@
+Missing navigation icons for network map
+vis.min.css is pointing to img/network/icon.png