Eslint warnings

Author: TatianaFomina

.eslintrc.js

@@ -3,5 +3,13 @@ module.exports = {
   env: {
     'node': true,
     'jest': true
+  },
+  rules: {
+    '@typescript-eslint/camelcase': 'warn',
+    '@typescript-eslint/no-unused-vars': 'warn',
+    '@typescript-eslint/explicit-function-return-type': 'warn',
+    'require-jsdoc': 'warn',
+    'no-shadow': 'warn',
+    'no-unused-expressions': 'warn'
   }
 };