Update expected size of the jar file in the first application getting started documentation

[tehnodev]

In section Creating an Executable Jar after "mvn package" command output example is text

The file should be around 10 MB in size.

Compiled example jar on java 17.0.6 is 17.6 MB, so maybe documentation should state around 18 MB in size

[wilkinsona]

Thanks for spotting this. I suspect that documentation was written around Spring Boot 1.0, if not even earlier and things have changed quite a bit since then. One of the most notable changes is that spring-boot-starter-web now includes Jackson by default. Other than that, much of the increase is accounted for by various modules increasing in size which all adds up.

[snicoll]

The size was actually fixed for 3.1.x onward by #32779