force pie_font text to stay inside the slice

Author: archmoj

test/image/baselines/pie_fonts.png

@@ -9,6 +9,7 @@
         "inherit from<br><b>global...</b>",
         "font"
       ],
+      "textposition": ["outside", "inside"],
       "type": "pie",
       "domain": {
         "x": [0, 0.4],