[PATCH v2] docs: process: email-client: add Thunderbird "Toggle Line Wrap" extension

[Vincent Mailhol <mailhol@kernel.org>]

While reading the git-format-patch manpages [1], I discovered the existence
of the "Toggle Line Wrap" extension for Thunderbird which I found rather
convenient.

Looking at the history, the ancestor of this extension was added to the
documentation in commit e0e34e977a7c ("Documentation/email-clients.txt:
update Thunderbird docs with wordwrap plugin") but then removed in commit
f9a0974d3f70 ("Documentation: update thunderbird email client settings").

Extend the paragraph on Thunderbird's mailnews.wraplength register to
mention the existence of the "Toggle Line Wrap" extension. The goal is not
to create a war on what is the best option so make it clear that this is
just an alternative.

[1] man git-format-patch -- §Thunderbird
Link: https://git-scm.com/docs/git-format-patch#_thunderbird

Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
Changes in v2:

  - Use the international URL (remove "fr/")

Link to v1: https://lore.kernel.org/r/20251225-docs_thunderbird-toggle-line-wrap-v1-1-24794afa4abf@kernel.org
---
 Documentation/process/email-clients.rst | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/process/email-clients.rst b/Documentation/process/email-clients.rst
index 84a2450bb6ec..b5377630a648 100644
--- a/Documentation/process/email-clients.rst
+++ b/Documentation/process/email-clients.rst
@@ -324,7 +324,14 @@ To beat some sense out of the internal editor, do this:
 
   - Set ``mailnews.send_plaintext_flowed`` to ``false``
 
-  - Set ``mailnews.wraplength`` from ``72`` to ``0``
+  - Set ``mailnews.wraplength`` from ``72`` to ``0`` **or** install the
+    "Toggle Line Wrap" extension
+
+    https://github.com/jan-kiszka/togglelinewrap
+
+    https://addons.thunderbird.net/thunderbird/addon/toggle-line-wrap
+
+    to control this registry on the fly.
 
 - Don't write HTML messages! Go to the main window
   :menuselection:`Main Menu-->Account Settings-->youracc@server.something-->Composition & Addressing`!

---
base-commit: 9448598b22c50c8a5bb77a9103e2d49f134c9578
change-id: 20251225-docs_thunderbird-toggle-line-wrap-dbe39bcb650b

Best regards,
-- 
Vincent Mailhol <mailhol@kernel.org>