Feat: add logging

.eslintrc

@@ -19,15 +19,7 @@
         ],
         "import/prefer-default-export": "off",
         "no-console": [
-            "error",
-            {
-                "allow": [
-                    "info",
-                    "warn",
-                    "trace",
-                    "error"
-                ]
-            }
+            "error"
         ]
     }
 }

CONTRIBUTING.md

@@ -0,0 +1,30 @@
+### Logger usage
+
+The project uses `pino` logger. This logger should be used over `console` calls.
+
+For usual in-file logging one should import the logger from the corresponding `logger.ts` module
+and use it in accordance with [documentation](https://github.com/pinojs/pino/tree/master/docs).
+
+In case of logging the processes that happen during http request handling it is also
+possible to use the dedicated logger that is accessible via the `express` request object.
+
+Here's a couple of examples:
+
+1. Http logging
+
+```typescript
+  // some resolver code above
+  resolve: (_parent, _args, ctx) => {
+      ctx.request.req.log.warn('dangerous');
+    });
+  },
+
+```
+
+2. Usual logger
+
+```typescript
+import logger from './logger'
+
+logger.info('Earth is flat')
+```