Fixed wysiwyg carret disappearing on Chrome (#652)

There's a bug where the carret doesn't show up when the text is first focused on Chrome with the previous combination of CSS. I tweaked it and now it seems to work (don't ask me why!).

Unfortunately on Safari, ever since we moved to contentEditable on #274, the carret disappeared the first time. I unsuccessfully tried to repro in a smaller codebase ( https://jsfiddle.net/u2mjs90y/1/ ) but it does work in Safari...

I'm not exactly sure what's going on, there are bunch of issues opened against this bug when googling against all the browsers...

src/element/textWysiwyg.tsx

@@ -39,7 +39,7 @@ export function textWysiwyg({
 
   Object.assign(editable.style, {
     color: strokeColor,
-    position: "fixed",
+    position: "absolute",
     opacity: opacity / 100,
     top: y + "px",
     left: x + "px",

src/styles.scss

@@ -3,6 +3,10 @@
 body {
   margin: 0;
   font-family: Arial, Helvetica, sans-serif;
+  overflow: hidden;
+  position: fixed;
+  width: 100%;
+  height: 100%;
   color: var(--text-color-primary);
 }