Improve spotlight example

[gkjohnson]

Related to #184

• Interesting example model
• One spotlight shining on it
• Swappable profiles with adjustable wall parameters

[gkjohnson]

Models:

• https://sketchfab.com/3d-models/horned-devil-caterpillar-alternative-style-febdbce61b45472da3de7d9a9878ef7a
• https://sketchfab.com/3d-models/street-food-vendor-challenge-kokorec-141db37d07fc4ccba84ab5f38a8181b5
• https://sketchfab.com/3d-models/thai-female-sandstone-sculpture-free-85a7ec2cc3f844d9bb02c5dae0f29b70
• https://sketchfab.com/3d-models/silent-ash-bc44272e8c1047148b33c913e659fcfa
• https://sketchfab.com/3d-models/globophobia-16d49263ed294d7ea7251e737a6bc3c4
• https://sketchfab.com/3d-models/pbr-kabuto-samurai-helmet-13b3ab49b6bd4247be36b54ba1a56d8a
• • https://sketchfab.com/3d-models/terrarium-bots-nerdscribbles-bf9a19aae6914a2c866311887edc8b3e

[gkjohnson]

• https://sketchfab.com/3d-models/world-war-robot-pumpkin-optimizer-0978fbf1f66f421f8b0cd896a191ab29
• https://sketchfab.com/3d-models/riding-robot-robottexturechallenge-fec5342649874a96b57d0a242f5da583
• • https://sketchfab.com/3d-models/steampunk-robot-dd1da8b32b0b43ad8c4060c86dc8d93c

[gkjohnson]

Demo model: steampunk-robot