[gimp-help] Update readme

[Jacob Boerema <jboerema src gnome org>]

commit bb0d9c59d688fc0dd6ae3a402c92f7aacbbd850d
Author: Jacob Boerema <jgboerema gmail com>
Date:   Tue Apr 6 12:22:30 2021 -0400

    Update readme
    
    - Add information for translators how to start.
    - Update and improve how to contribute to
      writing the manual.

 README | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)
---
diff --git a/README b/README
index bbbd10110..aed8652b8 100644
--- a/README
+++ b/README
@@ -20,10 +20,29 @@ Recent changes and updates about the modules are available at:
 Tips for contribution
 =====================
 
-Write a mail to one of the authors (check the WIKI).
-They should know what tasks need to be done and can find something to
-do for you. You should subscribe to the gimp mailing lists to get up
-to date information of the current GIMP development.
+If you are interested in translating the manual the best way to
+start is going to https://l10n.gnome.org/module/gimp-help/,
+register an account and apply to be a member of the language team
+for the language you want to translate.
+You can then start translating the po files of GIMP's manual found
+on that website.
+
+If instead you would like to help out writing and improving the
+manual then this is the right place to start.
+Preferrably build the most up to date manual yourself or check
+the latest uploaded version at https://docs.gimp.org/2.10/en/.
+
+The source of the manual can be found in XML files in the /src
+directory of this repository. Find a topic that interests you
+or that needs updating and start writing.
+
+It would be a good idea to subscribe to the gimp mailing lists,
+especially the developer and docs lists. That way you can keep
+up to date about the development of GIMP, see:
+https://www.gimp.org/mail_lists.html
+Most of the GIMP developers can also be reached on the #gimp
+IRC channel on irc.gimp.org. The best chances to talk are
+usually during European evening hours.
 
   What you should know
   --------------------