Scaladoc define syntax clashes with string interpolation

[janekdb]

In Scaladoc examples code block may contain interpolated strings. This result in a warning when the corresponding replacement text is not defined. If the replacement was defined replacement is unlikely to be desirable.

[warn] Console.scala:46: Variable RESET undefined in comment for object Console in object Console
[warn]  *          Console.err.println(s"${RESET}${YELLOW_B}${RED}${UNDERLINED}NO!${RESET}")

[janekdb]

Option	Comment
Turn off define substitution in code blocks	Attractive
Introduce new non-clashing syntax for define replacements	Attractive but introduces legacy and migration
Hide $s from the define replacement code in code blocks with escape syntax	Yuk!

[Lasering]

Related issue #9815

[som-snytt]

Duplicate.