Aleph viewer demo with astronaut GLB and label annotations

[JulieWinchester]

This is needed to complete #17. The acceptance criteria is the same as the criteria from #17 for initial demos. Will copy those criteria below.

Acceptance criteria for initial demos:

• Example demo using a viewer, perhaps in code sandbox, but could use other environments
• Demo should load the astronaut GLB
• Demo should create 2 label annotations:
  • Label 'visor' on the astronaut's visor (should add specific coordinates on face mask)
  • Label 'glove' on the astronaut's left glove (should add specific coordinates on left glove)
• Important: the annotations should be loaded from a JSON-format object, whether provided as its own file (and applied on initial load) or as input from a text field box (and applied dynamically in response to button input)

[JulieWinchester]

Aleph viewer demo that meets the criteria listed above: https://codesandbox.io/s/aleph-annotation-demo-teh3pf?file=/index.html

This demo loads annotations from an external JSON file with content:

{
  "nodes": [
    [
      "Visor",
      {
        "normal": "0.29259561389217825 0.11383937564155769 0.9494358342113489",
        "position": "0.017023790299119268 1.8062894401300538 0.34094835034109217",
        "scale": 0.025,
        "title": "Visor"
      }
    ],
    [
      "Glove",
      {
        "normal": "0.47124483745139667 0.05608789306010443 0.8802172751244348",
        "position": "0.5175891304384852 0.9555791975125096 0.12190797586809543",
        "scale": 0.025,
        "title": "Glove"
      }
    ]
  ]
}