Add helm-css-scss

https://github.com/ShingoFukuyama/helm-css-scss
Add a recipe for flycheck-tip
Recipe for dired-toggle-sudo

Summary: Browse files and directories with sudo privileges. With a
  simple keystroke, you can view and edit root files and directories.

Association with the package: I like the package a lot and contributed a
  commit years ago.

Repository: https://github.com/renard/dired-toggle-sudo/

Communication with package maintainer: none, the package was already
ready.

Tests: the package builds and installs properly.
Recipe for pier-mode

Summary: Emacs Major mode for Pier-formatted text files.

Association with the package: I am the maintainer.

Repository: https://github.com/DamienCassou/pier-cl

Communication with package maintainer: none, the package was already
ready.

Tests: the package builds and installs properly.
Adding docker-mode.
Remove defunct vlfi package
Add gore-mode

/cc @sergey-pashaev