git completion: 'git fetch' for remotes (#5253)

docs/sample_config/default_config.nu

@@ -14,6 +14,54 @@ module completions {
     ^git remote | lines | each { |line| $line | str trim }
   }
 
+  # Download objects and refs from another repository
+  export extern "git fetch" [
+    repository?: string@"nu-complete git remotes" # name of the branch to fetch
+    --all                                         # Fetch all remotes
+    --append(-a)                                  # Append ref names and object names to .git/FETCH_HEAD
+    --atomic                                      # Use an atomic transaction to update local refs.
+    --depth: int                                  # Limit fetching to n commits from the tip
+    --deepen: int                                 # Limit fetching to n commits from the current shallow boundary
+    --shallow-since: string                       # Deepen or shorten the history by date
+    --shallow-exclude: string                     # Deepen or shorten the history by branch/tag
+    --unshallow                                   # Fetch all available history
+    --update-shallow                              # Update .git/shallow to accept new refs
+    --negotiation-tip: string                     # Specify which commit/glob to report while fetching
+    --negotiate-only                              # Do not fetch, only print common ancestors
+    --dry-run                                     # Show what would be done
+    --write-fetch-head                            # Write fetched refs in FETCH_HEAD (default)
+    --no-write-fetch-head                         # Do not write FETCH_HEAD
+    --force(-f)                                   # Always update the local branch
+    --keep(-k)                                    # Keep dowloaded pack
+    --multiple                                    # Allow several arguments to be specified
+    --auto-maintenance                            # Run 'git maintenance run --auto' at the end (default)
+    --no-auto-maintenance                         # Don't run 'git maintenance' at the end
+    --auto-gc                                     # Run 'git maintenance run --auto' at the end (default)
+    --no-auto-gc                                  # Don't run 'git maintenance' at the end
+    --write-commit-graph                          # Write a commit-graph after fetching
+    --no-write-commit-graph                       # Don't write a commit-graph after fetching
+    --prefetch                                    # Place all refs into the refs/prefetch/ namespace
+    --prune(-p)                                   # Remove obsolete remote-tracking references
+    --prune-tags(-P)                              # Remove any local tags that do not exist on the remote
+    --no-tags(-n)                                 # Disable automatic tag following
+    --refmap: string                              # Use this refspec to map the refs to remote-tracking branches
+    --tags(-t)                                    # Fetch all tags
+    --recurse-submodules: string                  # Fetch new commits of populated submodules (yes/on-demand/no)
+    --jobs(-j): int                               # Number of parallel children
+    --no-recurse-submodules                       # Disable recursive fetching of submodules
+    --set-upstream                                # Add upstream (tracking) reference
+    --submodule-prefix: string                    # Prepend to paths printed in informative messages
+    --upload-pack: string                         # Non-default path for remote command
+    --quiet(-q)                                   # Silence internally used git commands
+    --verbose(-v)                                 # Be verbose
+    --progress                                    # Report progress on stderr
+    --server-option(-o): string                   # Pass options for the server to handle
+    --show-forced-updates                         # Check if a branch is force-updated
+    --no-show-forced-updates                      # Don't check if a branch is force-updated
+    -4                                            # Use IPv4 addresses, ignore IPv6 addresses
+    -6                                            # Use IPv6 addresses, ignore IPv4 addresses
+  ]
+
   # Check out git branches and files
   export extern "git checkout" [
     ...targets: string@"nu-complete git branches"   # name of the branch or files to checkout