Fix typo errors in SplitPane.kt (#5200)

This PR addresses typographical errors in the comments of the
`splitpane` package. The corrections are as follows:

1. **VerticalSplitPane function comment**:
- **Original**: "Pane that place it parts **vertically** from top to
bottom and allows to change items **heights**."
- **Correction**: "Pane that places its parts **vertically** from top to
bottom and allows changing items' **heights**."

2. **HorizontalSplitPane function comment**:
- **Original**: "Pane that place it parts **horizontally** from left to
right and allows to change items **width**."
- **Correction**: "Pane that places its parts **horizontally** from left
to right and allows changing items' **widths**."

3. **SplitPane function comment**:
- **Original**: "@param isHorizontal describes is it horizontal of
vertical split pane"
- **Correction**: "@param isHorizontal describes whether it is a
horizontal or vertical split pane"

These changes enhance the clarity and grammatical accuracy of the code
comments.

**Fixes** 

N/A

**Testing**

As these changes are limited to comments and do not affect the
executable code, no additional testing is required.

**Release Notes**

N/A

Since the changes are non-functional and pertain only to code comments,
they do not necessitate an entry in the release notes.

Author: luisgarcia96

components/SplitPane/library/src/commonMain/kotlin/org/jetbrains/compose/splitpane/SplitPane.kt

@@ -11,7 +11,7 @@ internal data class MinimalSizes(
 )
 
 /**
- * Pane that place it parts **vertically** from top to bottom and allows to change items **heights**.
+ * Pane that places it parts **vertically** from top to bottom and allows to change items' **heights**.
  * The [content] block defines DSL which allow you to configure top ([SplitPaneScope.first]),
  * bottom ([SplitPaneScope.second]).
  *
@@ -41,7 +41,7 @@ fun VerticalSplitPane(
 }
 
 /**
- * Pane that place it parts **horizontally** from left to right and allows to change items **width**.
+ * Pane that places it parts **horizontally** from left to right and allows to change items' **width**.
  * The [content] block defines DSL which allow you to configure left ([SplitPaneScope.first]),
  * right ([SplitPaneScope.second]) parts of split pane.
  *
@@ -74,7 +74,7 @@ fun HorizontalSplitPane(
 /**
  * Internal implementation of default splitter
  *
- * @param isHorizontal describes is it horizontal or vertical split pane
+ * @param isHorizontal describes whether it is a horizontal or vertical split pane
  * @param splitPaneState the state object to be used to control or observe the split pane state
  */
 @OptIn(ExperimentalSplitPaneApi::class)
@@ -104,4 +104,4 @@ internal expect fun SplitPane(
     first: (@Composable () -> Unit)?,
     second: (@Composable () -> Unit)?,
     splitter: Splitter
-)
+)