For example:
Guide to Panel Controlling
1: Make sure the panel is closed.
2: Once closed, open the other panel.
2.1: Do this and this...
You can also include in my requirements certain text styling and so on.
I am currently using Django and Jquery/Bootstrap with a MySQL DB. In the future, an iOS native app will need to display the same information. Therefore, if something is set as "1.2.3." in the web app, it will need to appear the same in the iOS app.
So my question (and it is very general) is: How can I store such things?
For example, if I was to store a recipe in a database. How can I then render the ingredients in a uniquely styled paragraph, followed by the steps in the recipe and so on.
If you take a look at Inkling, they do such thing. I don't feel like they store each chapter in an XML file and then render it. Wouldn't that create too much overhead?
This is a general question, so the answer is necessarily general. What you are describing is a hierarchical data structure: an ordered sequence of steps, each of which may be the parent of a sequence of sub-steps. The two standard ways of handling this in MySQL is with either an adjacency list or a nested set structure. Both of these structures are described in many places on the web. One nice write-up is this one by Mike Hillyer.
This doesn't address the formatting issues, but that's more about the kind of data you'll store at each node in the hierarchy, and is independent of how to represent the hierarchical structure itself.