fix format

d2format/format.go

@@ -358,6 +358,9 @@ func (p *printer) _map(m *d2ast.Map) {
 func (p *printer) mapKey(mk *d2ast.Key) {
 	if mk.Ampersand {
 		p.sb.WriteByte('&')
+	} else if mk.NotAmpersand {
+		p.sb.WriteByte('!')
+		p.sb.WriteByte('&')
 	}
 	if mk.Key != nil {
 		p.key(mk.Key)

d2format/format_test.go

@@ -829,6 +829,30 @@ mybox: {
 mybox: {
   label: prefix${test}suffix
 }
+`,
+		},
+		{
+			name: "not-filter",
+			in: `jacob: {
+	shape: circle
+}
+jeremy: {
+	shape: rectangle
+}
+*: {
+	!&shape: rectangle
+	label: I'm not a rectangle
+}`,
+			exp: `jacob: {
+  shape: circle
+}
+jeremy: {
+  shape: rectangle
+}
+*: {
+  !&shape: rectangle
+  label: I'm not a rectangle
+}
 `,
 		},
 	}