Automatically commit changes to .md files in a directory on save using grunt watch.

grunt.js

/*global module:false*/
module.exports = function(grunt) {

  // Project configuration.
  grunt.initConfig({
    exec: {
      commit: {
        command: function(grunt){
          var d        = new Date(),
              datetime = d.toString();
          return "git add *.md; git commit -m 'Document saved (" + datetime + ")'";
        }
      }
    },
    watch: {
      files: '*.md',
      tasks: 'exec'
    },
  });

  grunt.loadNpmTasks('grunt-exec');
  // Default task.
  grunt.registerTask('default', 'exec');

};