[PATCH] Documentation/email-clients.txt: Fix one grammar mistake, add extra info about TB

["Giedrius Statkevičius" <giedrius.statkevicius@gmail.com>]

Fix one grammar mistake (Allows->Allow) and add extra information about
the external editor add-on of Thunderbird: the developer must make sure
that their editor doesn't fork (IOW it mustn't return before closing)
thus they should be careful how they configure the addon. Furthermore,
add a tip how to do it with gvim.

Signed-off-by: Giedrius Statkevičius <giedrius.statkevicius@gmail.com>
---
 Documentation/email-clients.txt | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/email-clients.txt b/Documentation/email-clients.txt
index eede608..064eed5 100644
--- a/Documentation/email-clients.txt
+++ b/Documentation/email-clients.txt
@@ -211,13 +211,20 @@ Thunderbird (GUI)
 Thunderbird is an Outlook clone that likes to mangle text, but there are ways
 to coerce it into behaving.

-- Allows use of an external editor:
+- Allow use of an external editor:
   The easiest thing to do with Thunderbird and patches is to use an
   "external editor" extension and then just use your favorite $EDITOR
   for reading/merging patches into the body text.  To do this, download
   and install the extension, then add a button for it using
   View->Toolbars->Customize... and finally just click on it when in the
   Compose dialog.
+  Please note that "external editor" requires that your editor must not fork, or
+  in other words, the editor must not return before closing thus you may have to
+  pass additional flags or change the settings of your editor. Most notably if
+  you are using gvim then you must pass the -f option to gvim by putting
+  "/usr/bin/gvim -f" (if the binary is in /usr/bin) to the text editor field in
+  "external editor" settings. If you are using some other editor then please
+  read its manual to find out how to do this.

 To beat some sense out of the internal editor, do this:

--
2.3.2