Update negate gate symbol to be a single thick line

src/gates/Joke_NeGate.js

@@ -1,25 +1,16 @@
 import {GateBuilder} from "src/circuit/Gate.js"
 import {Matrix} from "src/math/Matrix.js"
+import {Point} from "src/math/Point.js"
 import {GatePainting} from "src/draw/GatePainting.js"
 
 const NeGate = new GateBuilder().
     setSerializedId("NeGate").
-    setSymbol("-I").
     setTitle("Ne-Gate").
     setBlurb("Negates all amplitudes.").
     setDrawer(args => {
         GatePainting.paintLocationIndependentFrame(args);
         let {x, y} = args.rect.center();
-        args.painter.print(
-            "-I",
-            x,
-            y,
-            'center',
-            'middle',
-            'black',
-            '16px monospace',
-            args.rect.w,
-            args.rect.h);
+        args.painter.strokeLine(new Point(x - 6, y), new Point(x + 6, y), 'black', 2);
     }).
     setKnownEffectToMatrix(Matrix.square(-1, 0, 0, -1)).
     gate;