Documentation improvement ideas

[JaniAnttonen]

There have been some usage-related issues that have been fixed in the comments, it's a good idea to incorporate these fixes to a some sort of troubleshooting section of the docs/readme:

• Winston-loki not working with Grafana Cloud Loki #108
• Can it used with frontend like react ? #60
• document header options #104
• TypeError: winston_loki_1.default is not a constructor #121
• Docs: Add a section to explain how to make it work with nextjs and/or webpack #129 (Could be a dependency issue, but still worth mentioning)
• Publish debug informations through the debug package #105 (Probably fixable with a config check in code)