Fix editor overflow: replace deprecated clip with hidden (#28)

## 💸 TL;DR
- The code editor was pushing the height of the UI beyond the view
height
- `overflow: clip` requires additional parameters to define the clip
margin and has other implications for scrolling
  - See: https://developer.mozilla.org/en-US/docs/Web/CSS/overflow#clip

## 📜 Details
[Design Doc](<!-- insert Google Doc link here if applicable -->)

[Jira](<!-- insert Jira link if applicable -->)

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employee

src/elements/play-pen/play-pen.ts

@@ -108,7 +108,7 @@ export class PlayPen extends LitElement {
       column-gap: 16px;
       display: flex;
       flex-direction: row;
-      overflow: clip;
+      overflow: hidden;
       padding-right: 16px;
       padding-left: 16px;
       row-gap: 16px;