docs(modifiers): Add TODOs for inspectableProperties lint warnings (#589)

The lint tool reported warnings for `ModifierNodeElement` classes
missing an override for `inspectableProperties`.
This function is used by development tools like the
Layout Inspector to display debug information.

Rather than implementing the function directly and adding complexity
to the existing minimal snippets, this commit adds `TODO` comments.
This serves as a reminder to create a dedicated snippet that demonstrates
how to properly implement `inspectableProperties`,
thereby keeping the current examples focused and clean while still
addressing the lint warning.

Author: cartland

compose/snippets/src/main/java/com/example/compose/snippets/modifiers/CustomModifierSnippets.kt

@@ -142,6 +142,7 @@ private class CircleNode(var color: Color) : DrawModifierNode, Modifier.Node() {
 }
 // [END android_compose_custom_modifiers_7]
 
+// TODO: Create a new snippet that overrides InspectorInfo.inspectableProperties.
 // [START android_compose_custom_modifiers_8]
 // ModifierNodeElement
 private data class CircleElement(val color: Color) : ModifierNodeElement<CircleNode>() {
@@ -159,6 +160,7 @@ fun Modifier.circle(color: Color) = this then CircleElement(color)
 // [END android_compose_custom_modifiers_9]
 
 private object CustomModifierSnippets10 {
+    // TODO: Create a new snippet that overrides InspectorInfo.inspectableProperties.
     // [START android_compose_custom_modifiers_10]
     // Modifier factory
     fun Modifier.circle(color: Color) = this then CircleElement(color)
@@ -181,6 +183,7 @@ private object CustomModifierSnippets10 {
     // [END android_compose_custom_modifiers_10]
 }
 
+// TODO: Create a new snippet that overrides InspectorInfo.inspectableProperties.
 // [START android_compose_custom_modifiers_11]
 fun Modifier.fixedPadding() = this then FixedPaddingElement