Copy-paste friendly executable comments in Ruby

Imagine this comment on top of a ruby file:
```ruby
### usage:
#### reset and seed database
# rake db:reset 
#### get korona base data
# rails runner 'Korona.synchronize_all!'
#### create valid day tickets in local development
# rails runner rails-runner/create_valid_ticket_for_shop_tests.rb
```
It is supposed to document the usage and gives executable example lines. However to use them verbatim you have to copy-paste them line by line, removing the leading `#`.

There is a better alternative using the [mostly frowned upon](https://stackoverflow.com/a/3000121/1162143) `=begin` / `=end` comment style:
```ruby
=begin usage:
rake db:reset                                                   # reset and seed database
rails runner 'Korona.synchronize_all!'                          # get korona base data
rails runner rails-runner/create_valid_ticket_for_shop_tests.rb # create valid day tickets in local development
=end
```

Now it is possible to copy-paste the whole block into a shell to execute.

alexanderpresber
March 16, 2023
