Upload a minimal documentation of how to implement a data ingress

[EdwinB12]

@mhauru wrote a lovely minimal use-case of how to implement the weather ingress:

import requests
from ingress_utils import backend_call, backend_login

CONST_OPENWEATHERMAP_FORECAST_URL = "https://api.openweathermap.org/data/3.0/onecall?lat=0&lon=0&units=metric&appid=<INSERT API KEY HERE>"
response = requests.get(CONST_OPENWEATHERMAP_FORECAST_URL)
openweather_data = response.json()
print(openweather_data)

access_token = backend_login(USERNAME, PASSWORD)

sensor_type_payload = {
    "name": "Weather",
    "measures": [...],
}
backend_call(
    "post", "/sensor/insert-sensor-type", sensor_type_payload, access_token=access_token
)

sensor_payload = {
    "sensor_type": "Weather",
    "unique_identifier": "The Weather Sensor",
    "name": "blah",
    ...,
}
backend_call(
    "post", "/sensor/insert-sensor", sensor_type, access_token=access_token
)

readings_payload = {
    "unique_identifier": "The Weather Sensor",
    "readings": ...,
    "timestamps": ...,
}

backend_call(
    "post", "/sensor/insert-sensor-readings", readings_payload, access_token=access_token
)

With a quick clean up and some comments, we could upload this as either an example or a readme maybe?