Add Makefile and Markdown linter (#73)

* Add Makefile

* Update .gitignore to exclude venv

* Add requirements.txt for venv

* Add pymarkdown lint Github action

* Update .md from lint tool

* Update README with make commands

* Add linter config

docs/Webhook.md

@@ -1,4 +1,5 @@
 # Webhook
+
 ## Purpose
 
 The idea behind this webhook feature is to provide an alternative to MQTT and InfluxDB for transmitting data, such as water meter readings from a vacation home, to a standard PHP webspace.
@@ -141,6 +142,7 @@ if ($method === 'POST') {
 ```
 
 ## Basic Example of a server using Python
+
 ```Python
 from flask import Flask, request, jsonify
 import csv