sway: insert numbered workspaces in order

fixes #308

Ordered by number ascending, with insert before same numbers.
Workspaces without numbers are appended at the end of the list.

Example order:
1 2:named 3:the_second 3:the_first 9 FIRST_NAME SECOND_NAME ...

1 files changed, 4 insertions, 0 deletions

diff --git a/include/layout.h b/include/layout.h
index 62e4c202..b7731031 100644
--- a/include/layout.h
+++ b/include/layout.h
@@ -24,6 +24,10 @@ int index_child(const swayc_t *child);
 // parent must be of type C_WORKSPACE or C_CONTAINER
 void add_child(swayc_t *parent, swayc_t *child);
 
+// Adds child to parent at index, if parent has no focus, it is set to child
+// parent must be of type C_WORKSPACE or C_CONTAINER
+void insert_child(swayc_t *parent, swayc_t *child, int index);
+
 // Adds child as floating window to ws, if there is no focus it is set to child.
 // ws must be of type C_WORKSPACE
 void add_floating(swayc_t *ws, swayc_t *child);