gh-122876: Fix "End of lines" typo (#125310)

Co-authored-by: Hugo van Kemenade <[email protected]>

Author: za

Doc/tutorial/introduction.rst

@@ -195,7 +195,7 @@ an odd number of ``\`` characters; see
 and workarounds.
 
 String literals can span multiple lines.  One way is using triple-quotes:
-``"""..."""`` or ``'''...'''``.  End of lines are automatically
+``"""..."""`` or ``'''...'''``.  End-of-line characters are automatically
 included in the string, but it's possible to prevent this by adding a ``\`` at
 the end of the line.  In the following example, the initial newline is not
 included::