correct spacing in String.xml (#9993)

Author: natelowry

xml/System/String.xml

@@ -16015,7 +16015,7 @@ The following example uses the <xref:System.String.Trim?displayProperty=nameWith
           ]]></format>
         </remarks>
         <block subset="none" type="usage">
-          <para>The .NET Framework 3.5 SP1 and earlier versions maintain an internal list of white-space characters that this method trims. Starting with the .NET Framework 4, the method trims all Unicode white-space characters (that is, characters that produce a <see langword="true" /> return value when they are passed to the <see cref="M:System.Char.IsWhiteSpace(System.Char)" /> method). Because of this change, the <see cref="M:System.String.Trim" /> method in the .NET Framework 3.5 SP1 and earlier versions removes two characters, ZERO WIDTH SPACE (U+200B) and ZERO WIDTH NO-BREAK SPACE (U+FEFF), that the <see cref="M:System.String.Trim" /> method in the .NET Framework 4and later versions does not remove. In addition, the <see cref="M:System.String.Trim" /> method in the .NET Framework 3.5 SP1 and earlier versions does not trim three Unicode white-space characters: MONGOLIAN VOWEL SEPARATOR (U+180E), NARROW NO-BREAK SPACE (U+202F), and MEDIUM MATHEMATICAL SPACE (U+205F).</para>
+          <para>The .NET Framework 3.5 SP1 and earlier versions maintain an internal list of white-space characters that this method trims. Starting with the .NET Framework 4, the method trims all Unicode white-space characters (that is, characters that produce a <see langword="true" /> return value when they are passed to the <see cref="M:System.Char.IsWhiteSpace(System.Char)" /> method). Because of this change, the <see cref="M:System.String.Trim" /> method in the .NET Framework 3.5 SP1 and earlier versions removes two characters, ZERO WIDTH SPACE (U+200B) and ZERO WIDTH NO-BREAK SPACE (U+FEFF), that the <see cref="M:System.String.Trim" /> method in the .NET Framework 4 and later versions does not remove. In addition, the <see cref="M:System.String.Trim" /> method in the .NET Framework 3.5 SP1 and earlier versions does not trim three Unicode white-space characters: MONGOLIAN VOWEL SEPARATOR (U+180E), NARROW NO-BREAK SPACE (U+202F), and MEDIUM MATHEMATICAL SPACE (U+205F).</para>
         </block>
         <altmember cref="M:System.String.TrimEnd(System.Char[])" />
         <altmember cref="M:System.String.TrimStart(System.Char[])" />