tools/web: Add sample react web app The sample app is currently the default vite starter template but with airmaranth protos built and used to call RPCs. Currently supports blinking LED + polling OnboardTemp and charting it using chartjs. See README.md for instructions. Change-Id: Ic2775a2ab200171322be40c1ce77cc1999488419 Reviewed-on: https://pigweed-internal-review.git.corp.google.com/c/pigweed/showcase/rp2/+/71152 Reviewed-by: Amy Hu <amyhu@google.com> Commit-Queue: Asad Memon <asadmemon@google.com>