Interpolated Strings in tr-lang

[kaiserthe13th]

Many other high-level languages have Interpolated strings, even some not so high-level languages have them (Crystal). So tr-lang should also have Interpolated strings. This comes along with a syntax proposal for such strings.

&"var = {var}"
# interpolates var into the string

or

(var)"var = {fmt}":fmt
# formats var into string with var:__fmt

Note: The 2nd proposal depends on #31