docs: add comprehensive getting started guide and linting configuration

backend/.eslintrc.json

@@ -0,0 +1,22 @@
+{
+  "env": {
+    "node": true,
+    "es2021": true
+  },
+  "extends": [
+    "eslint:recommended",
+    "plugin:@typescript-eslint/recommended"
+  ],
+  "parser": "@typescript-eslint/parser",
+  "parserOptions": {
+    "ecmaVersion": "latest",
+    "sourceType": "module"
+  },
+  "plugins": [
+    "@typescript-eslint"
+  ],
+  "rules": {
+    "@typescript-eslint/no-unused-vars": "warn",
+    "@typescript-eslint/no-explicit-any": "warn"
+  }
+}