Adjusted linting process

* Define globals in .eslintrc.js rather than in each script (only
  includes already used globals for now, but should include all globals
  available in Tiled).

* Disable the quotes lint, since it's not clear why one style should be
  enforced.

.eslintrc.js

@@ -16,13 +16,18 @@ module.exports = {
 			"error",
 			"unix"
 		],
-		"quotes": [
-			"error",
-			"double"
-		],
 		"semi": [
 			"error",
 			"always"
 		]
+	},
+	"globals": {
+		"File": "readonly",
+		"FileInfo": "readonly",
+		"MapObject": "readonly",
+		"TextFile": "readonly",
+		"TileLayer": "readonly",
+		"TileMap": "readonly",
+		"tiled": "readonly"
 	}
 };

find-layer-by-id.js

@@ -8,8 +8,6 @@
  * you know its ID.
  */
 
-/* global tiled */
-
 function findLayerById(thing, id) {
 	for (let i = thing.layerCount - 1; i >= 0; i--) {
 		const layer = thing.layerAt(i);

find-object-by-id.js

@@ -11,8 +11,6 @@
  * function to work properly for isometric maps.
  */
 
-/* global tiled */
-
 function findObjectById(thing, id) {
 	for (let i = thing.layerCount - 1; i >= 0; i--) {
 		const layer = thing.layerAt(i);

follow-warp.js

@@ -12,8 +12,6 @@
  * with some adjustments it probably could!
  */
 
-/* global tiled */
-
 /**
  * @param thing {TileMap | GroupLayer}
  * @param name {string}

rectangle-chain.js

@@ -7,8 +7,6 @@
  * the map.
  */
 
-/* global tiled, MapObject */
-
 tiled.registerTool("RectangleChain", {
 	name: "Draw Rectangle Chain",
 	icon: "rectangle-chain.svg",

remove-unused-tilesets.js

@@ -9,8 +9,6 @@
  * automatically on save.
  */
 
-/* global tiled */
-
 /**
  * @param {TileMap} map
  */

shortcuts.mjs

@@ -18,8 +18,6 @@
  * the Preferences dialog.
  */
 
-/* global tiled */
-
 /**
  * @param {Tileset} tileset
  */

tile-rectangle.js

@@ -10,8 +10,6 @@
  * brush is repeated in all directions.
  */
 
-/* global tiled, TileLayer, TileMap */
-
 tiled.registerTool("PaintTileRectangle", {
 	name: "Paint Tile Rectangle",
 	icon: "tile-rectangle.svg",

videogame-format.js

@@ -8,8 +8,6 @@
  * method from the videogame library (https://github.com/diogoeichert/videogame)
  */
 
-/* global tiled, FileInfo, TextFile */
-
 tiled.registerMapFormat("videogame", {
 	name: "videogame map format",
 	extension: "json",