Now the memory defaults of master and slave in Standalone mode and History Server is 1g, not 512m. So let's update docs.

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #7896 from sarutak/update-doc-for-daemon-memory and squashes the following commits:

a77626c [Kousuke Saruta] Fix docs to follow the update of increase of memory defaults