Add initial traffic signs to CSON
user
```coffeescript
{
  information_pedestrian_crossing:
    category: 'other'
    name: 'pedestrian crossing'
    elements: [
      { type: 'tri-bg', value: 'white' }
      { type: 'tri-o', value: 'red' }
      { type: 'pedestrian', value: 'black' }
    ]

  mandatory_keep_right:
    category: 'mandatory'
    name: 'keep right'
    elements: [
      { type: 'circle-bg', value: 'blue' }
      { type: 'arrow-45-r', value: 'white' }
    ]

  mandatory_keep_left:
      category: 'mandatory'
      name: 'keep left'
      elements: [
        { type: 'circle-bg', value: 'blue' }
        { type: 'arrow-45-l', value: 'white' }
      ]
}
```
assistant