Fix mongoose docs generation

PUBLISHED_FROM=331821dcd1f7dc8a94581cd8a9b51aa00a89fddc

docs/c-api/mg_net.h/mg_event_handler_t.md

@@ -0,0 +1,12 @@
+---
+title: "mg_event_handler_t"
+decl_name: "mg_event_handler_t"
+symbol_kind: "typedef"
+signature: |
+  typedef void (*mg_event_handler_t)(struct mg_connection *nc, int ev,
+                                     void *ev_data MG_UD_ARG(void *user_data));
+---
+
+Callback function (event handler) prototype. Must be defined by the user.
+Mongoose calls the event handler, passing the events defined below. 
+