WIP: Start rendering lines from DisplayLayers

src/text-editor.coffee

@@ -117,6 +117,7 @@ class TextEditor extends Model
       @config, @assert, @grammarRegistry, @packageManager
     })
     @buffer = @displayBuffer.buffer
+    @displayLayer = buffer.addDisplayLayer({tabLength})
     @selectionsMarkerLayer ?= @addMarkerLayer(maintainHistory: true)
 
     for marker in @selectionsMarkerLayer.getMarkers()