chore: add ES Lint

.eslintignore

@@ -0,0 +1,3 @@
+# Ignore anything outside of the packages' src directories
+/*
+!/src

.eslintrc.json

@@ -0,0 +1,44 @@
+{
+  "env": {
+    "node": true
+  },
+  "extends": [
+    "eslint:recommended",
+    "plugin:@typescript-eslint/recommended",
+    "plugin:import/recommended",
+    "plugin:import/typescript"
+  ],
+  "parser": "@typescript-eslint/parser",
+  "plugins": [
+    "@typescript-eslint",
+    "import"
+  ],
+  "rules": {
+    "@typescript-eslint/explicit-member-accessibility": "error",
+    "@typescript-eslint/indent": [
+      "error",
+      2
+    ],
+    "@typescript-eslint/no-parameter-properties": "off",
+    "@typescript-eslint/type-annotation-spacing": [
+      "error",
+      {
+        "before": true
+      }
+    ],
+    "linebreak-style": [
+      "error",
+      "unix"
+    ],
+    "prefer-const": "error",
+    "quotes": [
+      "error",
+      "double"
+    ],
+    "semi": [
+      "error",
+      "always"
+    ],
+    "no-undef": "off"
+  }
+}

package.json

@@ -11,6 +11,10 @@
     "watch": "parcel -p 8080 watch src/ui/index.html"
   },
   "devDependencies": {
+    "@typescript-eslint/eslint-plugin": "^3.7.1",
+    "@typescript-eslint/parser": "^3.7.1",
+    "eslint": "^7.6.0",
+    "eslint-plugin-import": "^2.22.0",
     "parcel-bundler": "^1.12.4",
     "sass": "^1.26.10",
     "tile-extruder": "^2.0.6",