Template:Documentation is used to add instructions on how to use a template, including an explanation of its syntax and parameters, recommended usage, and example code. When added to a page, it will transclude a subpage found at Template:YOURTEMPLATE/doc (which initially will be a red link) – write your documentation on that subpage.
Usage
Place the following at the bottom of a template:
<noinclude>{{Documentation}}</noinclude>
This must come directly after the last character in your template – do not place it on a new line.
Example
If you have a template to create bold text that looks like this:
'''{{{1}}}'''
Add the documentation template like this:
'''{{{1}}}'''<noinclude>{{Documentation}}</noinclude>