Add Maia introduction section to quickstart part 1.

[RyanMocke]

Adds a new "Build Faster with Maia" section to the Responsive Web App quickstart guide (Part 1), introducing Maia to beginners after they've completed the manual build steps.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
2 out of 3 committers have signed the CLA.

✅ quinntracy
✅ ConnorLand
❌ Mocke44
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