docs: add refdocs for AspectRatio

Author: thatfiredev

firebase-ai/src/main/kotlin/com/google/firebase/ai/type/AspectRatio.kt

@@ -19,15 +19,25 @@ package com.google.firebase.ai.type
 /** Represents the aspect ratio that the generated image should conform to. */
 public class AspectRatio private constructor(internal val internalVal: String) {
   public companion object {
+    /** A square image, useful for icons, profile pictures, etc. */
     @JvmField public val SQUARE_1x1: AspectRatio = AspectRatio("1:1")
-    @JvmField public val PORTRAIT_2x3: AspectRatio = AspectRatio("2:3")
-    @JvmField public val LANDSCAPE_3x2: AspectRatio = AspectRatio("3:2")
+    /** A portrait image in 3:4, the aspect ratio of older TVs. */
     @JvmField public val PORTRAIT_3x4: AspectRatio = AspectRatio("3:4")
+    /** A landscape image in 4:3, the aspect ratio of older TVs. */
     @JvmField public val LANDSCAPE_4x3: AspectRatio = AspectRatio("4:3")
-    @JvmField public val PORTRAIT_4x5: AspectRatio = AspectRatio("4:5")
-    @JvmField public val LANDSCAPE_5x4: AspectRatio = AspectRatio("5:4")
+    /** A portrait image in 9:16, the aspect ratio of modern monitors and phone screens. */
     @JvmField public val PORTRAIT_9x16: AspectRatio = AspectRatio("9:16")
+    /** A landscape image in 16:9, the aspect ratio of modern monitors and phone screens. */
     @JvmField public val LANDSCAPE_16x9: AspectRatio = AspectRatio("16:9")
+    /** A portrait image in 4:5, the aspect ratio for prints from digital cameras. */
+    @JvmField public val PORTRAIT_4x5: AspectRatio = AspectRatio("4:5")
+    /** A landscape image in 5:4, the aspect ratio for prints from digital cameras. */
+    @JvmField public val LANDSCAPE_5x4: AspectRatio = AspectRatio("5:4")
+    /** A portrait image in 4:5, the aspect ratio for prints from 35mm film cameras. */
+    @JvmField public val PORTRAIT_2x3: AspectRatio = AspectRatio("2:3")
+    /** A landscape image in 4:5, the aspect ratio for prints from 35mm film cameras. */
+    @JvmField public val LANDSCAPE_3x2: AspectRatio = AspectRatio("3:2")
+    /** A ultrawide image in 21:9, an aspect ratio commonly used in modern movies. */
     @JvmField public val LANDSCAPE_21x9: AspectRatio = AspectRatio("21:9")
   }
 }