I have prepared a very nice article for sending text messages and want to publish it here on Stack Exchange. How to do that?
You don't. Stack Exchange sites are not blogs.
If you can formulate your article as a question which is not too broad, or opinion based, and a subsequent answer, you could post it here, but I highly doubt if you can rewrite it that far.
A blog might be more suitable for your article.
Short answer; you don't.
Stack Exchange is a series of question and answer sites; as such, it is not the appropriate place to simply post articles we have created on a particular topic.
We can certainly publish material we have written without somebody else asking about it, but we should/must also ensure that:
- We are formatting the content as a quality question and answer, and not a "how-to".
- We are posting a question that would be useful to other users.
- We are posting a question/answer that is of quality format, with an emphasis on "straight to the point", and direct, definitive answers over discussion-orientated ones.
- We are posting the content on a site where the content falls within the scope of both Stack Exchange, and what that site considers to be on-topic.
It is next to impossible to tell if your article would be appropriate anywhere, but it is certainly inappropriate for Stack Overflow (a programming-focused site). I can easily speculate that anything written as an article would still require extensive format to be left open, let alone received well. I would recommend looking for a blogging platform for self-publishing articles.