Tweak wording for root of web app question.

[jeffposnick]

R: @gauntface

Fixes #1237

[workbox-pr-bot]

PR-Bot Size Plugin

Changed File Sizes

File	Before	After	Change	GZipped
packages/workbox-cli/build/bin.js	2.77 KB	2.55 KB	-8%	1.08 KB
packages/workbox-webpack-plugin/build/generate-sw.js	5.89 KB	5.84 KB	-1%	2.04 KB
packages/workbox-webpack-plugin/build/inject-manifest.js	8.00 KB	7.95 KB	-1%	2.65 KB

New Files

No new files have been added.

All File Sizes

View Table

File	Before	After	Change	GZipped
packages/workbox-background-sync/build/workbox-background-sync.prod.js	3.23 KB	3.23 KB	0%	1.38 KB
packages/workbox-broadcast-cache-update/build/workbox-broadcast-cache-update.prod.js	1.07 KB	1.07 KB	0%	574 B
packages/workbox-build/build/_types.js	41 B	41 B	0%	61 B
packages/workbox-build/build/index.js	2.52 KB	2.52 KB	0%	1.06 KB
packages/workbox-cache-expiration/build/workbox-cache-expiration.prod.js	3.41 KB	3.41 KB	0%	1.27 KB
packages/workbox-cacheable-response/build/workbox-cacheable-response.prod.js	598 B	598 B	0%	350 B
packages/workbox-cli/build/app.js	4.57 KB	4.57 KB	0%	1.65 KB
packages/workbox-cli/build/bin.js	2.77 KB	2.55 KB	-8%	1.08 KB
packages/workbox-core/build/workbox-core.prod.js	6.40 KB	6.40 KB	0%	2.54 KB
packages/workbox-google-analytics/build/workbox-google-analytics.prod.js	2.07 KB	2.07 KB	0%	1.02 KB
packages/workbox-precaching/build/workbox-precaching.prod.js	5.18 KB	5.18 KB	0%	2.02 KB
packages/workbox-range-requests/build/workbox-range-requests.prod.js	1.66 KB	1.66 KB	0%	816 B
packages/workbox-routing/build/workbox-routing.prod.js	2.77 KB	2.77 KB	0%	1.26 KB
packages/workbox-strategies/build/workbox-strategies.prod.js	3.24 KB	3.24 KB	0%	1.01 KB
packages/workbox-sw/build/workbox-sw.js	1.46 KB	1.46 KB	0%	796 B
packages/workbox-webpack-plugin/build/generate-sw.js	5.89 KB	5.84 KB	-1%	2.04 KB
packages/workbox-webpack-plugin/build/index.js	742 B	742 B	0%	470 B
packages/workbox-webpack-plugin/build/inject-manifest.js	8.00 KB	7.95 KB	-1%	2.65 KB

Workbox Aggregate Size Plugin

☠️ WARNING ☠️

We are using 154% of our max size budget.

Total Size: 22.53KB
Percentage of Size Used: 154%

Gzipped: 9.03KB