Removed information from 3 topics

[Jennifer Hodgdon]

I wanted to let you know that on this issue:
https://www.drupal.org/project/user_guide/issues/3007090
we made a change to the English source file(s) install-composer.txt, install-decide.txt, security-update-core.txt :

We removed text that suggested downloading modules, themes, and core software using Git. We decided this was not so appropriate for the User Guide, which is aimed at beginners.

Here is the commit for reference:
https://cgit.drupalcode.org/user_guide/commit/?id=0cbaa4c

Suggested actions to respond to this change in each language would be either:
a) If the file hasn't been translated yet, copy the English source file to your language directory and commit it.
b) If the file has already been translated, open a new issue to revise the translation.

  --Jennifer