Properly link flecs library

engine/libs/flecs/examples/c/explorer/src/main.c

@@ -0,0 +1,47 @@
+#include <explorer.h>
+
+typedef struct {
+    double value;
+} Mass;
+
+int main(int argc, char *argv[]) {
+    // Passing in the command line arguments will allow the explorer to display
+    // the application name.
+    ecs_world_t *world = ecs_init_w_args(argc, argv);
+
+    ECS_IMPORT(world, FlecsUnits);
+    ECS_IMPORT(world, FlecsMonitor); // Collect statistics periodically
+
+    // Mass component
+    ECS_COMPONENT(world, Mass);
+
+    ecs_struct(world, {
+        .entity = ecs_id(Mass),
+        .members = {
+            { .name = "value", .type = ecs_id(ecs_f64_t), .unit = EcsKiloGrams}
+        }
+    });
+
+    // Simple hierarchy
+    ecs_entity_t Sun = ecs_new_entity(world, "Sun");
+    ecs_set(world, Sun, Mass, {1.988500e31});
+
+    ecs_set_scope(world, Sun);
+    ecs_entity_t Earth = ecs_new_entity(world, "Earth");
+    ecs_set(world, Earth, Mass, {5.9722e24});
+
+    ecs_set_scope(world, Earth);
+    ecs_entity_t Moon = ecs_new_entity(world, "Moon");
+    ecs_set(world, Moon, Mass, {7.34767309e22});
+
+    // Restore default hierarchy scope to root
+    ecs_set_scope(world, 0);
+    
+    // Run application with REST interface. When the application is running,
+    // navigate to https://flecs.dev/explorer to inspect it!
+    //
+    // See docs/RestApi.md#explorer for more information.
+    return ecs_app_run(world, &(ecs_app_desc_t){
+        .enable_rest = true
+    });
+}