feat(filter): add camel_case filter and auto_lightness filter

[TanX-009]

Add camel_case filter

primary_container -> primaryContainer
secondary_container -> secondaryContainer

Usage

<* for name, value in colors *>
${{name | camel_case}}: {{value.default.hex}};
<* endfor *>

Add auto_lightness filter

• #ff0000 as hex color input gives
  • (light to dark)
    {{ colors.primary_container.default.hex }} gives #ffdad4
{{ colors.primary_container.default.hex | auto_lightness: 20.0 }} gives #ff826e
  • (dark to light)
    {{ colors.primary_container.default.hex }} gives #73342a
{{ colors.primary_container.default.hex | auto_lightness: 20.0 }} gives #bc5747