In the United States, luxury-car buyers are snapping up Teslas and other electric cars that cost more than $60,000, and even relatively cheap models cost more than $25,000. Here in India, those are all out of reach of the vast majority of families, whose median income is just $2,400. But an electric vehicle movement is taking place nonetheless, not on four wheels, but on two and three. Electric mopeds and three-wheeled rickshaw taxis that sell for as little as $1,000 are zipping along India’s congested urban thoroughfares, cheered on by…