[FEATURE] allow opting-out of templating for a setting

[ibotty]

Is your feature request related to a problem? Please describe.
Some files should just not be templated (think bash scripts). I know I can add {% raw %} ... {% endraw %} to every file.

Describe the solution you'd like
Maybe add another option to settings, like

bashrc_d = { source = "bashrc", target = ".config/bashrc.d", templating = false }

Defaulting that option to true is the right approach for backwards compat and feels right.

Describe alternatives you've considered
none.