Update instances of Now to Vercel where applicable

[timothyis]

This pull request renames various instances of now to vercel etc. in order to match content that's being updated on the Vercel platform.

[timothyis]

One of the main areas I've avoided updating here is functional code like:

next.js/packages/next/build/index.ts

Line 170 in 0fc344e

hasNowJson: !!(await findUp('now.json', { cwd: dir })),

[lfades]

💯

[ijjk]

Stats from current PR

Default Server Mode (Increase detected ⚠️)

General

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
buildDuration	11.6s	11.7s	⚠️ +125ms
nodeModulesSize	66 MB	66 MB	✓

Page Load Tests Overall increase ✓

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.197	2.087	-0.11
/ avg req/sec	1137.69	1197.73	⚠️ +60.04
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.557	1.393	-0.16
/error-in-render avg req/sec	1605.93	1795.24	⚠️ +189.31

Client Bundles (main, webpack, commons)

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
main-HASH.js gzip	6.59 kB	6.59 kB	✓
webpack-HASH.js gzip	746 B	746 B	✓
de003c3a9d30..6c2a.js gzip	10.5 kB	10.5 kB	✓
framework.HASH.js gzip	39.1 kB	39.1 kB	✓
Overall change	57 kB	57 kB	✓

Client Bundles (main, webpack, commons) Modern

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
main-HASH.module.js gzip	5.67 kB	5.67 kB	✓
webpack-HASH..dule.js gzip	746 B	746 B	✓
de003c3a9d30..dule.js gzip	6.93 kB	6.93 kB	✓
framework.HA..dule.js gzip	39.1 kB	39.1 kB	✓
Overall change	52.5 kB	52.5 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
polyfills-HASH.js gzip	26.3 kB	26.3 kB	✓
Overall change	26.3 kB	26.3 kB	✓

Client Pages

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
_app.js gzip	1.26 kB	1.26 kB	✓
_error.js gzip	3.25 kB	3.25 kB	✓
hooks.js gzip	881 B	881 B	✓
index.js gzip	222 B	222 B	✓
link.js gzip	2.05 kB	2.05 kB	✓
routerDirect.js gzip	279 B	279 B	✓
withRouter.js gzip	278 B	278 B	✓
Overall change	8.21 kB	8.21 kB	✓

Client Pages Modern

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
_app.module.js gzip	604 B	604 B	✓
_error.module.js gzip	2.04 kB	2.04 kB	✓
hooks.module.js gzip	383 B	383 B	✓
index.module.js gzip	223 B	223 B	✓
link.module.js gzip	1.51 kB	1.51 kB	✓
routerDirect..dule.js gzip	281 B	281 B	✓
withRouter.m..dule.js gzip	278 B	278 B	✓
Overall change	5.32 kB	5.32 kB	✓

Client Build Manifests

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
_buildManifest.js gzip	61 B	61 B	✓
_buildManife..dule.js gzip	61 B	61 B	✓
Overall change	122 B	122 B	✓

Rendered Page Sizes

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
index.html gzip	924 B	924 B	✓
link.html gzip	934 B	934 B	✓
withRouter.html gzip	922 B	922 B	✓
Overall change	2.78 kB	2.78 kB	✓

---

Serverless Mode

General

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
buildDuration	12.6s	12.6s	-70ms
nodeModulesSize	66 MB	66 MB	✓

Client Bundles (main, webpack, commons)

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
main-HASH.js gzip	6.59 kB	6.59 kB	✓
webpack-HASH.js gzip	746 B	746 B	✓
de003c3a9d30..6c2a.js gzip	10.5 kB	10.5 kB	✓
framework.HASH.js gzip	39.1 kB	39.1 kB	✓
Overall change	57 kB	57 kB	✓

Client Bundles (main, webpack, commons) Modern

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
main-HASH.module.js gzip	5.67 kB	5.67 kB	✓
webpack-HASH..dule.js gzip	746 B	746 B	✓
de003c3a9d30..dule.js gzip	6.93 kB	6.93 kB	✓
framework.HA..dule.js gzip	39.1 kB	39.1 kB	✓
Overall change	52.5 kB	52.5 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
polyfills-HASH.js gzip	26.3 kB	26.3 kB	✓
Overall change	26.3 kB	26.3 kB	✓

Client Pages

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
_app.js gzip	1.26 kB	1.26 kB	✓
_error.js gzip	3.25 kB	3.25 kB	✓
hooks.js gzip	881 B	881 B	✓
index.js gzip	222 B	222 B	✓
link.js gzip	2.05 kB	2.05 kB	✓
routerDirect.js gzip	279 B	279 B	✓
withRouter.js gzip	278 B	278 B	✓
Overall change	8.21 kB	8.21 kB	✓

Client Pages Modern

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
_app.module.js gzip	604 B	604 B	✓
_error.module.js gzip	2.04 kB	2.04 kB	✓
hooks.module.js gzip	383 B	383 B	✓
index.module.js gzip	223 B	223 B	✓
link.module.js gzip	1.51 kB	1.51 kB	✓
routerDirect..dule.js gzip	281 B	281 B	✓
withRouter.m..dule.js gzip	278 B	278 B	✓
Overall change	5.32 kB	5.32 kB	✓

Client Build Manifests

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
_buildManifest.js gzip	61 B	61 B	✓
_buildManife..dule.js gzip	61 B	61 B	✓
Overall change	122 B	122 B	✓

Serverless bundles

	vercel/next.js canary	vercel/next.js update-now-to-vercel	Change
_error.js	878 kB	878 kB	✓
404.html	4.18 kB	4.18 kB	✓
hooks.html	3.81 kB	3.81 kB	✓
index.js	879 kB	879 kB	✓
link.js	916 kB	916 kB	✓
routerDirect.js	909 kB	909 kB	✓
withRouter.js	909 kB	909 kB	✓
Overall change	4.5 MB	4.5 MB	✓