Reading documentation on an ereader is a much more pleasant experience than on a screen. Spring Boot has an epub book available, which isn’t supported by the Kindle, but fortunately can be easily converted.
First of all download the epub, then install some tools used by the Calibre ebook software. This includes the ebook-convert standalone program, so use that to convert the epub into Kindle’s mobi format.
You can download the documentation for Spring Boot 1.4.0 to have a look at the generated file. When this goes out of date, you can generate a new version yourself.