Only escape backslashes and single quotes in SanitizeKeyValue

this documentation is correct:
https://ffmpeg.org/ffmpeg-utils.html

this is outdated:
https://ffmpeg.org/ffmpeg-formats.html#metadata

TwitchDownloaderCore/Tools/FfmpegMetadata.cs

@@ -94,17 +94,14 @@ private static string SanitizeKeyValue(string str)
                 return str;
             }
 
-            if (str.AsSpan().IndexOfAny(@$"=;#\{LINE_FEED}") == -1)
+            if (str.AsSpan().IndexOfAny(@$"\'") == -1)
             {
                 return str;
             }
 
             return new StringBuilder(str)
-                .Replace("=", @"\=")
-                .Replace(";", @"\;")
-                .Replace("#", @"\#")
                 .Replace(@"\", @"\\")
-                .Replace(LINE_FEED, $@"\{LINE_FEED}")
+                .Replace("'", @"\'")
                 .ToString();
         }
     }