Add resources to world

- setResource(name, resource) to set a resource
- getResource(name) to retrieve it

concord/world.lua

@@ -36,6 +36,8 @@ function World.new()
       __events     = {},
       __emitSDepth = 0,
 
+      __resources = {},
+
       __hash = {
          state = -2^53,
          generator = defaultGenerator,
@@ -474,6 +476,22 @@ end
 function World:onEntityRemoved(e) -- luacheck: ignore
 end
 
+--- Sets a named resource in the world
+-- @string name Name of the resource
+-- @tparam Any resource Resource to set
+-- @treturn World self
+function World:setResource(name, resource)
+  self.__resources[name] = resource
+  return self
+end
+
+--- Gets a named resource from the world
+-- @string name Name of the resource
+-- @treturn Any resource
+function World:getResource(name)
+  return self.__resources[name]
+end
+
 return setmetatable(World, {
    __call = function(_, ...)
       ---@diagnostic disable-next-line: redundant-parameter