fix CDATA section (#3402)

Author: mairaw

xml/System/String.xml

@@ -14119,8 +14119,7 @@ The following example uses the <xref:System.String.Trim?displayProperty=nameWith
         <summary>Removes all leading and trailing instances of a character from the current string.</summary>
         <returns>The string that remains after all instances of the <paramref name="trimChar" /> character are removed from the start and end of the current string. If no characters can be trimmed from the current instance, the method returns the current instance unchanged.</returns>
         <remarks>
-          <format type="text/markdown">
-  <![CDATA[
+          <format type="text/markdown"><![CDATA[
 
 ## Remarks
 
@@ -14186,8 +14185,7 @@ If the current string equals <xref:System.String.Empty?displayProperty=nameWitht
         <summary>Removes all leading and trailing occurrences of a set of characters specified in an array from the current string.</summary>
         <returns>The string that remains after all occurrences of the characters in the <paramref name="trimChars" /> parameter are removed from the start and end of the current string. If <paramref name="trimChars" /> is <see langword="null" /> or an empty array, white-space characters are removed instead. If no characters can be trimmed from the current instance, the method returns the current instance unchanged.</returns>
         <remarks>
-          <format type="text/markdown">
-  <![CDATA[
+          <format type="text/markdown"><![CDATA[
 
 ## Remarks
 
@@ -14355,8 +14353,7 @@ The `TrimEnd(System.Char)` method removes from the current string all trailing `
         <summary>Removes all the trailing occurrences of a set of characters specified in an array from the current string.</summary>
         <returns>The string that remains after all occurrences of the characters in the <paramref name="trimChars" /> parameter are removed from the end of the current string. If <paramref name="trimChars" /> is <see langword="null" /> or an empty array, Unicode white-space characters are removed instead. If no characters can be trimmed from the current instance, the method returns the current instance unchanged.</returns>
         <remarks>
-          <format type="text/markdown">
-  <![CDATA[
+          <format type="text/markdown"><![CDATA[
 
 ## Remarks