refactor: keep local branch list order in completions for certain commands (#60)

This MR prevents the default **local* branch list sorting (alphabetical order) in completions (current behaviour) and preserves git branch sorting by **recency** instead (via `__fish_git_branches`).

Those changes will help navigate to latest committed branches quickly in completions when using either `move`, `merge` or `tag` commands. In particular, when having many local branches.
See Fish shell `complete` command for more details.

Commands affected:
- merge
- move
- tag

Author: joseluisq

completions/merge.fish

@@ -5,7 +5,7 @@
 
 __gitnow_load_git_functions
 
-complete -f -x -c merge -a '(__fish_git_branches)'
+complete -f -k -x -c merge -a '(__fish_git_branches)'
 
 complete -f -x -c merge \
     -s h -l help \

completions/move.fish

@@ -5,27 +5,27 @@
 
 __gitnow_load_git_functions
 
-complete -f -x -c move -a '(__fish_git_branches)'
+complete -f -k -x -c move -a '(__fish_git_branches)'
 
-complete -f -x -c move \
+complete -f -k -x -c move \
     -s h -l help \
     -d "Show information about the options for this command"
 
 complete -f -x -c move \
     -s p -l prev \
     -d "Switch to a previous branch using the `--no-apply-stash` option (equivalent to \"move -\")"
 
-complete -f -x -c move \
+complete -f -k -x -c move \
     -s n -l no-apply-stash \
     -a '(__fish_git_branches)' \
     -d "Switch to a local branch but without applying current stash"
 
-complete -f -x -c move \
+complete -f -k -x -c move \
     -s u -l upstream \
     -a '(__fish_git_branches)' \
     -d "Fetch a remote branch and switch to it applying current stash"
 
-complete -f -x -c move \
+complete -f -k -x -c move \
     -s r -l remote-branch \
     -n 'contains -- -u (commandline -opc); or contains -- --upstream (commandline -opc)' \
     -a '(__fish_git_branches)' \

completions/tag.fish

@@ -5,10 +5,10 @@
 
 __gitnow_load_git_functions
 
-complete -f -x -c tag \
+complete -f -k -x -c tag \
     -d "List all tags in a lexicographic order and treating tag names as versions"
 
-complete -f -x -c tag -a '(__fish_git_tags)'
+complete -f -k -x -c tag -a '(__fish_git_tags)'
 
 complete -f -x -c tag \
     -s h -l help \