package/btrfs-progs: update Kconfig package homepage URL

The btrfs-progs homepage [1] show a banner:

    OBSOLETE CONTENT
    This wiki has been archived and the content is no longer updated.

    NOTE: this wiki is archived and not updated anymore (02/2023).
    Contents will be migrated to https://btrfs.readthedocs.io

This commit updates the URL to the new one at [2].

[1] https://btrfs.wiki.kernel.org/index.php/Main_Page
[2] https://btrfs.readthedocs.io

Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/btrfs-progs/Config.in

@@ -10,7 +10,7 @@ config BR2_PACKAGE_BTRFS_PROGS
 	help
 	  Btrfs filesystem utilities
 
-	  https://btrfs.wiki.kernel.org/index.php/Main_Page
+	  https://btrfs.readthedocs.io
 
 comment "btrfs-progs needs a toolchain w/ threads"
 	depends on BR2_USE_MMU