docs: add missing reference to $XDG_CONFIG_HOME Signed-off-by: Ran Benita <ran@unusedvar.com>
diff --git a/xkbcommon/xkbcommon.h b/xkbcommon/xkbcommon.h
index 559d5d7..bf14e5c 100644
--- a/xkbcommon/xkbcommon.h
+++ b/xkbcommon/xkbcommon.h
@@ -530,7 +530,7 @@ xkb_keysym_to_lower(xkb_keysym_t ks);
*
* The user may set some environment variables which affect the library:
*
- * - `XKB_CONFIG_ROOT`, `HOME` - see @ref include-path.
+ * - `XKB_CONFIG_ROOT`, `XDG_CONFIG_DIR`, `HOME` - see @ref include-path.
* - `XKB_LOG_LEVEL` - see xkb_context_set_log_level().
* - `XKB_LOG_VERBOSITY` - see xkb_context_set_log_verbosity().
* - `XKB_DEFAULT_RULES`, `XKB_DEFAULT_MODEL`, `XKB_DEFAULT_LAYOUT`,