docs: remove translation instructions

(Moved to https://github.com/fish-shell/fish-shell/wiki/Translations)
Fix for quoted variables in command position error message
https://github.com/fish-shell/fish-shell/issues/775
Make funced properly handle an invalid number of arguments
Fixes https://github.com/fish-shell/fish-shell/issues/780
git prompt: Fix hang on detached head.

$git_dir was never set in __fish_git_prompt_current_branch, but used
in the case of a detached HEAD.  This caused `cut -c1-7 $git_dir/HEAD`
to expand to `cut -c1-7` which then waited for input.
Mark jobs as completed when all processes have finished, not just the last one.
Fixes https://github.com/fish-shell/fish-shell/issues/876 , and coincidentally also https://github.com/fish-shell/fish-shell/issues/848
Fix for incorrect use of shared ptr references
Cleanup of code that decides whether or not to fork. Fix for issue where stderr may be output twice.
Added completions for Vagrant
Portmaster completions

* Added FreeBSD's pkg to __fish_print_packages
* Portmaster completes on installed packages and ports
* Options list as per fish_generate_completions, needs to be tidied
  up further but will suffice for now