Improvement/rit completion

[viniciussousazup]

- What I did
Add support to fish and powershell on rit completion

- How to verify it
read the tutorial on: rit completion fish --help
read the tutorial on: rit completion powershell --help

- Description for the changelog
Rit now support fish and powershell on completion

[codecov-commenter]

Codecov Report

Merging #245 into master will increase coverage by 0.40%.
The diff coverage is 84.00%.

@@            Coverage Diff             @@
##           master     #245      +/-   ##
==========================================
+ Coverage   66.19%   66.59%   +0.40%     
==========================================
  Files          73       73              
  Lines        2754     2799      +45     
==========================================
+ Hits         1823     1864      +41     
- Misses        672      674       +2     
- Partials      259      261       +2     

Impacted Files	Coverage Δ
pkg/autocomplete/autocomplete.go	100.00% <ø> (ø)
pkg/cmd/root.go	0.00% <0.00%> (ø)
pkg/autocomplete/generator.go	95.65% <76.47%> (-4.35%)	⬇️
pkg/cmd/autocomplete.go	96.55% <100.00%> (+3.21%)	⬆️
pkg/formula/watcher/watcher.go	76.47% <0.00%> (+5.88%)	⬆️

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