Improper backslashes (\) appear in front of underscores in generated markdown manual

[chad-earthscope]

https://github.com/EarthScope/slinktool/blob/02c9d0c15793ac75722aa13aebb25ded7b2d118a/doc/slinktool.md#examples

e.g.:

> slinktool -v -S GE\_WLF,MN\_AQU:00???,IU\_KONO:BHZ.D :18010