💄 Use ''' instead of '\''

This leads to a problem in Emacs due to a bug in julia-emacs:

JuliaEditorSupport/julia-emacs#142

Author: ronisbr

src/backends/text/predefined_formats.jl

@@ -28,7 +28,7 @@ const ascii_dots = TextFormat(
 const ascii_rounded = TextFormat(
     up_right_corner     = '.',
     up_left_corner      = '.',
-    bottom_left_corner  = '\'',
+    bottom_left_corner  = ''',
     bottom_right_corner = ''',
     up_intersection     = '.',
     left_intersection   = ':',