Fix Grid get/set typedefs

lib/data-structures/grid.js

@@ -95,28 +95,46 @@ export class Grid {
   }
 
   /**
+   * @template T the datatype that has been set in the grid for this position
    * @overload
    * @param {Vector2} x
-   * @returns {?} "TODO@v1" attempt to get this template-ized
+   * @returns {T}
    */
   /**
+   * @template T the datatype that has been set in the grid for this position
    * @overload
    * @param {Integer} x
    * @param {Integer} y
-   * @returns {?}
+   * @returns {T}
    */
   /**
+   * @template T the datatype that has been set in the grid for this position
    * @param {Integer | Vector2} x
    * @param {Integer} [y]
-   * @returns {?}
+   * @returns {T}
    */
   get(x, y) {
     // @ts-expect-error TS can't handle overloads calling overloads
     return this.#grid[this.#index(x, y)]
   }
 
+
+  /**
+   * @template T the datatype to hold in this position
+   * @overload
+   * @param {Vector2} vec
+   * @param {T} value
+   * @returns {void}
+   */
+  /**
+   * @template T the datatype to hold in this position
+   * @overload
+   * @param {Integer} x
+   * @param {Integer} y
+   * @param {T} value
+   * @returns {void}
+   */
   /**
-   * TODO@v1: add overload notations
    * @param {[number, number, any] | [Vector2, any]} args
    * @returns {void}
    */