Kevin Marquette shows how to create a micro module and explains why you might want one:
A micro module is very small in scope and often has a single function. Building a micro module is about getting back to the basics and keeping everything as simple as possible.
There is a lot of good advice out there on how to build a module. That guidance is there to assist you as your module grows in size. If we know that our module will not grow and we will not add any functions, we can take a different approach even though it may not conform fully to the community best practices.
There are a few things which differ from standard module best practices.