[misc] setup eslint and prettier and fix any errors

package.json

@@ -2,6 +2,12 @@
   "name": "sharelatex",
   "version": "0.0.1",
   "description": "An online collaborative LaTeX editor",
+  "scripts": {
+    "lint": "eslint --max-warnings 0 --format unix .",
+    "lint:fix": "eslint --fix .",
+    "format": "prettier --list-different $PWD/'**/*.js'",
+    "format:fix": "prettier --write $PWD/'**/*.js'"
+  },
   "dependencies": {
     "async": "^0.9.0",
     "bson": "^1.0.4",
@@ -21,11 +27,22 @@
   "devDependencies": {
     "grunt": "~0.4.2",
     "bunyan": "~0.22.1",
+    "eslint": "^7.21.0",
+    "eslint-config-prettier": "^8.1.0",
+    "eslint-config-standard": "^16.0.2",
+    "eslint-plugin-chai-expect": "^2.2.0",
+    "eslint-plugin-chai-friendly": "^0.6.0",
+    "eslint-plugin-import": "^2.22.1",
+    "eslint-plugin-mocha": "^8.0.0",
+    "eslint-plugin-node": "^11.1.0",
+    "eslint-plugin-promise": "^4.2.1",
+    "eslint-plugin-standard": "^5.0.0",
     "grunt-bunyan": "~0.5.0",
     "grunt-execute": "~0.1.5",
     "grunt-available-tasks": "~0.4.1",
     "grunt-concurrent": "~0.4.3",
     "grunt-contrib-coffee": "~0.10.1",
+    "prettier": "^2.2.1",
     "semver": "~2.2.1",
     "knox": "~0.8.9"
   }