merge: Combine duration transformers into single file

Co-authored-by: lukasoppermann <[email protected]>

Author: Copilot

src/index.ts

@@ -33,8 +33,7 @@ import {cubicBezierCss} from './transformer/cubic-bezier-css.js'
 import {dimensionPixelToRem} from './transformer/dimension-pixel-to-rem.js'
 import {dimensionRemToPixel} from './transformer/dimension-rem-to-pixel.js'
 import {dimensionToPixelUnitless} from './transformer/dimension-to-pixelUnitless.js'
-import {durationMsToS} from './transformer/duration-ms-to-s.js'
-import {durationSToMs} from './transformer/duration-s-to-ms.js'
+import {durationMsToS, durationSToMs} from './transformer/duration.js'
 import {fontCss} from './transformer/font-css.js'
 import {fontFamilyCss} from './transformer/font-family-css.js'
 import {fontWeightToNumber} from './transformer/font-weight-to-number.js'