[mod] SearXNG JavaScript Style Guide (eslint:recommended)

The SearXNG JavaScript Style Guide is a set of eslint rules [1] based on the
eslint:recommended [2] rules.

    "extends": "eslint:recommended"

The additional rules adopted from the JavaScript Standard Style [3][4].

[1] https://eslint.org/docs/rules/
[2] https://github.com/kunalgolani/eslint-config/tree/master/packages/recommended
[3] https://standardjs.com/rules.html#javascript-standard-style
[4] https://github.com/standard/eslint-config-standard/blob/master/.eslintrc.json

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/static/themes/simple/package.json

@@ -30,6 +30,7 @@
     "all": "npm install && grunt",
     "build": "grunt",
     "eslint": "grunt eslint",
+    "eslint-fix": "grunt eslint --fix",
     "watch": "grunt watch",
     "webfont": "grunt webfont",
     "clean": "rm -Rf node_modules package-lock.json ion.less",