rack static framework

basic router; erb views

erb/md/html files:

 file.erb     : html format
 file_md.erb  : markdown
 layout.erb   : main layout template 
 not_found_md.erb   : custom 404 handler view 
 file.html    : html file

directories:

erb files    :  views/
html files   :  public/
assets files :  public/css/,
                public/img/,
                public/js/

define routes hash:

{'/path' => :name }  # name_erb
{'/path' => :name_md } # name_md.erb
{'/root_path' => '#html_name' } # name.html
{'/sub_path' => 'dir#html_name' } # dir/name.html
{'/path_a', '/path_x' => :name } # shared path, quasi-redirection

    get('/path_1', '/path_n'){ :file_md }
    get('/html'){ '#index' }
    get('/subfolder'){ 'ruby#index' }
    
    Router.map['/about'] = :about
    Router['/', '/home'] = :index
    Router.map.merge!('/first' => :first, '/next'=> :next )