Standard way for usethis to manage part of a file

[hadley]

By surrounding lines of code with comments

Use in:

• use_badge(), replacing home grown solution
• use_rcpp(), use_tibble() for NAMESPACE management (roxygen2 or otherwise)
• use_conflicted(), use_reprex() etc for .Rprofile insertion

[jennybc]

If you customize your Emacs preferences via the built-in "Easy Customization" tool (hahaha), you get entries prefaced like this at the end of ~/.emacs:

;; custom-set-variables was added by Custom.
;; If you edit it by hand, you could mess it up, so be careful.
;; Your init file should contain only one such instance.
;; If there is more than one, they won't work right.

[hadley]

I'm not going to include the .Rprofile stuff right now because it doesn't seem as important, and needs more infrastructure in block_insert() so we can have extra explanatory text around it.