Follow up to #30476: Using jupyter kernelspec to install sagemath kernel results in copying about 2Gb of documentation into the jupyter kernels share directory. That's generally not the spot to put large files/documentation. Document how to avoid this.

Component: documentation

Author: Nils Bruin

Branch/Commit: 79914c2

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/31620