Add alias gct for forgit::checkout::tag in fish

[sandr01d]

Check list

• [X] I have performed a self-review of my code
• [ ] I have commented my code in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation

Description

Noticed there was another alias missing for fish. This is the last one :)

Type of change

• [X] Bug fix
• [ ] New feature
• [ ] Refactor
• [ ] Breaking change
• [ ] Documentation change

Test environment

• Shell
  • [ ] bash
  • [ ] zsh
  • [X] fish
• OS
  • [X] Linux
  • [ ] Mac OS X
  • [ ] Windows
  • [ ] Others:

[cjappl]

Damn, all of these fish things I've been missing out on.....

Thanks for catching this!