docs(nxdev): add /docs redirect rule

[bcabanes]

It adds a redirect rule for /docs to /getting-started/intro on nx.dev.

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✅ Successfully ran 12 targets

• nx affected --target=e2e --base=26e710180b2ee9be9f47516ae4736eff719cdea6 --head=af5ed5c32e2736ade31a3ccac5ee7052b33b8cd5 --exclude=e2e-storybook,e2e-storybook-angular,e2e-react-native,e2e-detox,e2e-make-angular-cli-faster --parallel=1
• nx affected --target=build --base=26e710180b2ee9be9f47516ae4736eff719cdea6 --head=af5ed5c32e2736ade31a3ccac5ee7052b33b8cd5 --parallel=3
• nx-cloud record -- yarn depcheck
• nx affected --target=test --base=26e710180b2ee9be9f47516ae4736eff719cdea6 --head=af5ed5c32e2736ade31a3ccac5ee7052b33b8cd5 --parallel=1
• nx affected --target=lint --base=26e710180b2ee9be9f47516ae4736eff719cdea6 --head=af5ed5c32e2736ade31a3ccac5ee7052b33b8cd5 --parallel=3
• nx-cloud record -- yarn nx workspace-lint
• nx-cloud record -- yarn check-lock-files
• nx-cloud record -- yarn check-commit
• nx-cloud record -- yarn nx format:check --base=26e710180b2ee9be9f47516ae4736eff719cdea6 --head=af5ed5c32e2736ade31a3ccac5ee7052b33b8cd5
• nx-cloud record -- yarn check-imports
• nx-cloud record -- yarn documentation
• nx build typedoc-theme

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Name	Status	Preview	Updated
nx-dev	✅ Ready (Inspect)	Visit Preview	Oct 3, 2022 at 5:03PM (UTC)

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