#15 Request: command for Dutch weather forecast

Return Dutch forecast for 1 day when '!knmi' is issued.

Source of the text returned will be the first paragraph of this page: https://knmi.nl/nederland-nu/weer/verwachtingen (or any better parseable source, e.g. an xml document published by knmi.nl)

Can use as a source document: ftp://ftp.knmi.nl/pub_weerberichten/basisverwachting.xml

Extract report->data->block where field_id=='Verwachting' and valid_id=='dag00_01', then use content of field_content.

Also end the returned text with https://knmi.nl/nederland-nu/weer/verwachtingen to serve both as a credit and as a pointer for extended forecast information.

If ftp://ftp.knmi.nl/pub_weerberichten/knmi_waarschuwingen_nl.txt exists, add an extra line with the contents of the first 3 paragraphs of that file.

Instead of the FTP links can also use RSS feeds:

• http://projects.knmi.nl/RSSread/rss_KNMIverwachtingen.php
• http://projects.knmi.nl/RSSread/rss_KNMIwaarschuwingen.php

Example usage for golang: https://stackoverflow.com/questions/25332175/golang-rss-xml-parsing-atom10link-overrides-link

Re-opened: extend the output with an alert message if applicable.

Closing, splitting off alert request through issue #22.