I'm quitting the company where I worked for one year. I was the only developer, and the product is a web application. The boss really appreciated me; he is sad that I'm leaving. He does not want to hire somebody right now and wants to call me sometimes for quick missions (a few days by month). I said it's not a good idea (because maybe I will not have time or will not want to work for it and other reasons), but he is sure of his choice. And he said if I am not available, he can call one other dev team he knows. And he said he will hire a new CTO(?!) in 6 months.
So, now, I'm preparing the code for my departure. Some classes are well documented, some are not, so I'm adding documentation REALLY everywhere. I'm coding more and more unit tests for some uncovered parts. And I'm adding more automated browser tests for critical path. I'm also writing documentation for day-to-day use (how to restore database, how to stop continuous deployment and so on) and documentation about architecture. I'm preparing code because I want it to be easy to getting started for the next developer (I will not have time to teach them anything, because it's in months).
The code is OK I guess (I worked alone, so I'm sure I made a lot of mistakes, but the application is pretty simple, I'm an experienced developer, and the stack is classic).
Should I continue to do this (add documentation, clean code, etc.) or what else should I be doing?