documentation: add compat=ignore_receive_errors option

doc/btrbk.conf.5.asciidoc

@@ -400,12 +400,29 @@ If you want to set this option for regular (non-root) user only, set
 *backend_local_user*.
 --
 
-*compat* busybox|no::
+*compat* <compat-option>...::
-    If set to ``busybox'', use busybox compatible commands. Defaults
+    Enable compatibility options. Available 'compat-option':
-    to ``no''.
++
-    If you want to set this option for local or remote hosts only, you
+--
-    can set *compat_local* or *compat_remote*
+*busybox*::
-    (e.g. "compat_remote busybox").
+    Use busybox compatible commands, at the expense of slight overhead
+    while reading filesystem information.
+
+*ignore_receive_errors*  _*experimental*_::
+    Tell btrfs-receive(8) to not terminate on errors by setting
+    "--max-errors=0" option. Print warnings instead.
++
+A known use case for this are target hosts lacking xattr support
+(e.g. some Synology NAS), while the send-stream contains "lsetxattr"
+commands. Another case is targets failing to set otime, complaining
+with "ERROR: attribute 12 requested but not present".
++
+Note that there is *no guarantee that backups created with this
+option enabled can be restored at all*.
+
+If you want to set this option for local or remote hosts only, set
+*compat_local* or *compat_remote* (e.g. "compat_remote busybox").
+--
 
 *cache_dir* <directory>::
     If set, cache extent maps for the "btrbk extents" command.