Add ability to read rustfmt.toml

atom-beautifier runs rustfmt in a tmp folder and rustfmt with not pick up
the rustfmt.toml file in any of the crate root folders or its parent folders.
This commit adds the --config-path parameter with the current folder and will
load any rust format in the file's path

Also set the --write-output format to override from the default setting replace.
This will avoid creating an unnecessary backup file tmp source file

src/beautifiers/rustfmt.coffee

@@ -14,9 +14,19 @@ module.exports = class Rustfmt extends Beautifier
   }
 
   beautify: (text, language, options) ->
+
+    # get file path which is the search path for rustfmt.toml as
+    # the beautifier runs rustfmt in a tmp directory.
+    # This will pick up any rustfmt.toml defined in the crate root
+
+    editor = atom.workspace.getActivePaneItem()
+    file = editor?.buffer.file
+    filePath = file?.path
     program = options.rustfmt_path or "rustfmt"
     @run(program, [
       tmpFile = @tempFile("tmp", text)
+      ["--write-mode", "overwrite"]
+      ["--config-path", filePath]
       ], help: {
         link: "https://github.com/nrc/rustfmt"
         program: "rustfmt"