The preferred way to contribute would be through GitHub pull requests,
as an alternative patches can be discussed on the IRC channel.

When contributing your first changes, please include an empty commit for
copyright waiver using the following message (replace 'John Doe' with
your name or nickname):

  John Doe Copyright Waiver

  I dedicate any and all copyright interest in this software to the
  public domain.  I make this dedication for the benefit of the public at
  large and to the detriment of my heirs and successors.  I intend this
  dedication to be an overt act of relinquishment in perpetuity of all
  present and future rights to this software under copyright law.

The command to create an empty commit from the command-line is:

  git commit --allow-empty
