[PATCH v2] Add basic b4 config file

[Baptiste Le Duc <baptiste.le-duc@xxxxxxxxxx>]

b4[1] is a convenient tool for mail-based contribution. A config file[2]
tracked in the tree lets the project ship a few defaults that match the Xen
patch submission rules.

This aims to help new contributors who have never used a mailing list avoid
mistakes when sending their patch series.

The tree has no scripts/checkpatch.pl or equivalent, so there is nothing
for b4 to run per patch. Disable the needs-checking pre-flight check so a
series can be sent without first running b4 prep --check.

[1] https://pypi.org/project/b4/
[2] https://b4.docs.kernel.org/en/latest/config.html

Signed-off-by: Baptiste Le Duc <baptiste.le-duc@xxxxxxxxxx>
---
Changes in v2:
- Drop Xen's patches submission rules from comment
- Drop flags that are not supported by get_maintainer.pl script, --nogit is
  supported but is a default so drop it also.
- Link to v1: 
https://patch.msgid.link/20260911-add-b4-config-v1-1-9a4ac1d2d569@xxxxxxxxxx
---
 .b4-config | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/.b4-config b/.b4-config
new file mode 100644
index 0000000000..e5e2435ec4
--- /dev/null
+++ b/.b4-config
@@ -0,0 +1,10 @@
+#
+# Common b4 settings for sending patches to the Xen Project upstream.
+# https://b4.docs.kernel.org/
+#
+
+[b4]
+       send-series-to = xen-devel@xxxxxxxxxxxxxxxxxxxx
+       send-auto-to-cmd = echo
+       send-auto-cc-cmd = ./scripts/get_maintainer.pl
+       midmask = https://lore.kernel.org/xen-devel/%s

---
base-commit: acd87f99ac65ff9426dd52f9b7a6ef9db45cc735
change-id: 20260911-add-b4-config-9ebfaf55a323

Best regards,
--  
Baptiste Le Duc <baptiste.le-duc@xxxxxxxxxx>