Add and configure ESLint and update configuration for Prettier (#617)

* Add ESLint, update Prettier

* Update docs

* Update tests

* Update licenses

* Fix review points

.prettierrc.js

@@ -0,0 +1,10 @@
+module.exports = {
+  printWidth: 80,
+  tabWidth: 2,
+  useTabs: false,
+  semi: true,
+  singleQuote: true,
+  trailingComma: 'none',
+  bracketSpacing: false,
+  arrowParens: 'avoid'
+};