Improve \ in string literal to show both effects (#50820)

Author: adamyakes

docs/fsharp/language-reference/strings.md

@@ -50,7 +50,7 @@ let xmlFragment1 = @"<book author=""Milton, John"" title=""Paradise Lost"">"
 let xmlFragment2 = """<book author="Milton, John" title="Paradise Lost">"""
 ```
 
-In code, strings that have line breaks are accepted and the line breaks are interpreted as the newline encoding used in source, unless a backslash character is the last character before the line break. Leading white space on the next line is ignored when the backslash character is used. The following code produces a string `str1` that has value `"abc\ndef"` and a string `str2` that has value `"abcdef"`.
+In code, strings that have line breaks are accepted and the line breaks are interpreted as the newline encoding used in source, unless a backslash character is the last character before the line break. Leading white space on the next line is ignored when the backslash character is used. The following code produces a string `str1` that has value `"abc\n     def"` and a string `str2` that has value `"abcdef"`.
 
 [!code-fsharp[Main](~/samples/snippets/fsharp/lang-ref-1/snippet1001.fs)]
 

samples/snippets/fsharp/lang-ref-1/snippet1001.fs

@@ -1,7 +1,7 @@
 let str1 =
     "abc
-def"
+     def"
 
 let str2 =
     "abc\
-def"
+     def"