[gimp-web] content: change link for editing the book list.

[Jehan <jehanp src gnome org>]

commit 6f0ea46b9ff6e08decd0381075887fb0b9549f84
Author: Jehan <jehan girinstud io>
Date:   Tue Jun 7 21:54:49 2022 +0200

    content: change link for editing the book list.
    
    Rather than proposing to contribute modifications to the markdown file
    (which implies understand how Gitlab works, merge requests and so on),
    let's just link to the bug report page and ask people to simply give us
    the same info as other books for easy copy-paste.
    
    Asking people to contribute directly to the file was technically a good
    idea, but maybe a bit "over" for just a book listing.

 content/books/index.md | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
---
diff --git a/content/books/index.md b/content/books/index.md
index a9a7d9bf..1971640a 100644
--- a/content/books/index.md
+++ b/content/books/index.md
@@ -11,10 +11,8 @@ reported by the community.
 we are notified of.
 
 ⚠️ *We are missing many books published the last few years. To add a book
-to this list, please [contribute
-modifications](https://gitlab.gnome.org/Infrastructure/gimp-web/-/blob/testing/content/books/index.md).
-<br/>The file format is *markdown* (you may also look and copy the syntax
-used for listing other books). Keep the order by publication date.* ⚠️
+to this list, please [report the same information as other books on the
+page](https://gitlab.gnome.org/Infrastructure/gimp-web/-/issues/new).*
 
 * [Books in English](#english)
 * [Books in Spanish](#espanol-spanish)