gnucash-docs maint: Minor improvements in C and de Help Tips on alphavantage

[Frank H.Ellenberger]

Updated	 via  https://github.com/Gnucash/gnucash-docs/commit/389b357e (commit)
	from  https://github.com/Gnucash/gnucash-docs/commit/e02cf7fc (commit)



commit 389b357e8fa208dacec89da85ceeffca017be25a
Author: Frank H. Ellenberger <frank.h.ellenberger at gmail.com>
Date:   Sat Jun 5 21:21:40 2021 +0200

    Minor improvements in C and de Help Tips on alphavantage



Summary of changes:
 help/C/Help_tips-appendix.xml  |  6 +++++-
 help/de/Help_tips-appendix.xml | 16 ++++++++++------
 2 files changed, 15 insertions(+), 7 deletions(-)