added dartfmt completions

completion/available/dartfmt.completion.bash

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+# ------------------------------------
+# Original Credits : https://github.com/claudiodangelis/dart-bash_completion
+# ------------------------------------
+if command -v docgen > /dev/null; then
+    _dartfmt() {
+        local cur prev opts
+        COMPREPLY=()
+        cur="${COMP_WORDS[COMP_CWORD]}"
+        prev="${COMP_WORDS[COMP_CWORD-1]}"
+
+        # Options
+        opts="--help --write --transform --max_line_length --machine"
+
+        # TODO: complete only *.dart files
+
+        if [[ ${cur} == -* ]] ; then
+            COMPREPLY=( $(compgen -W "${opts}" -- ${cur}) )
+            return 0
+        else
+            COMPREPLY=()
+            return 0
+        fi
+
+    }
+
+    complete -o default -F _dartfmt dartfmt
+fi