gnucash-docs maint: Use entity for aphavantage URL and improve grouping of entities

[Frank H.Ellenberger]

Updated	 via  https://github.com/Gnucash/gnucash-docs/commit/30d6b14d (commit)
	from  https://github.com/Gnucash/gnucash-docs/commit/06f4b052 (commit)



commit 30d6b14d966dad7b4c8920b7703247e874d8cc3f
Author: Frank H. Ellenberger <frank.h.ellenberger at gmail.com>
Date:   Thu Sep 26 11:36:45 2019 +0200

    Use entity for aphavantage URL and improve grouping of entities



Summary of changes:
 docbook/gnc-docbookx.dtd       |   16 +-
 help/C/Help_ch_Customize.xml   |    5 +-
 help/C/Help_tips-appendix.xml  |   18 +-
 help/de/Help_tips-appendix.xml | 7949 ++++++++++++++++++++--------------------
 4 files changed, 4013 insertions(+), 3975 deletions(-)