Publish debug informations through the debug package

[clouedoc]

Hi! 👋

Firstly, thanks for creating this life-saving package! 🙂

Today I used patch-package to patch [email protected] for the project I'm working on.

My problem was that I added a double-slash at the end of my Loki URL.
e.g. I supplied http://host/ instead of http://host

The patch I'm submitting will help others debug this kind of problem in the future.
I suggest using the almost-standard debug package to supply the user with debugging information.

To enable printing of the debugging information, the user only has to define the following environment variable:

DEBUG=winston-loki

By using this environment variable, the user will get debug information printed to the console like so:

Here is a rough implementation example:

diff --git a/node_modules/winston-loki/src/requests.js b/node_modules/winston-loki/src/requests.js
index 5f57fdc..18a7af3 100644
--- a/node_modules/winston-loki/src/requests.js
+++ b/node_modules/winston-loki/src/requests.js
@@ -1,5 +1,6 @@
 const http = require('http')
 const https = require('https')
+const debug = require('debug')('winston-loki')
 
 const post = async (lokiUrl, contentType, headers = {}, data = '', timeout) => {
   // Construct a buffer from the data string to have deterministic data size
@@ -25,6 +26,8 @@ const post = async (lokiUrl, contentType, headers = {}, data = '', timeout) => {
       timeout: timeout
     }
 
+    debug("sending options: " + JSON.stringify(options, undefined, 2))
+
     // Construct the request
     const req = lib.request(options, res => {
       let resData = ''
@@ -34,6 +37,7 @@ const post = async (lokiUrl, contentType, headers = {}, data = '', timeout) => {
 
     // Error listener
     req.on('error', error => {
+      debug("loki HTTP error: " + error)
       reject(error)
     })
 

I'm interested in creating a PR for this feature.

Thank you for your attention.