Add PayPal donation button to Jekyll site

_config.yml

donations:
  paypal:
    text:           Donate      # Button text
    id:             7334HG9754  # PayPal button ID

donations-paypal.html

{% if site.donations.paypal %}
  <form class="paypalform" action="https://www.paypal.com/cgi-bin/webscr" method="post">
    <input type="hidden" name="cmd" value="_s-xclick">
    <input type="hidden" name="hosted_button_id" value="{{ site.donations.paypal.id | default: 'UNCONFIGURED' }}">
    <button class="donations uk-button uk-button-primary" name="submit">
      <span>{{ site.donations.paypal.text | default: 'Donations' }}</span>
    </button>
    <img alt="" border="0" src="https://www.paypal.com/en_US/i/scr/pixel.gif" width="1" height="1">
  </form>
{% endif %}

example-page-include.md

{% include donations-paypal.html %}