Aggregate weather for entries when importing

[thekid]

THis pull request fetches the weather from OpenMeteo and displays it below the date and locations for each entry:

Requirements

For the OpenMeteo API to produce correct results, contents must have a timezone set. This can be done by adding the Olson timezone name behind the date in the *.md files. In the following example, the timezone is Asia/Muscat:

title: "Wadi Dayqah-Stausee"
date: 2024-11-24 12:30 Asia/Muscat
location: {name: "Wadi Dayqah, Qurayyat, Oman", link: "https://maps.app.goo.gl/Norm7ue7ejTXQkGY7"}

Icons

The icons in use are from https://basmilius.github.io/weather-icons/, which provides them MIT-licensed. They are bundled in src/main/webapp/static/weather using the following command line:

#!/bin/sh

used=src/main/handlebars/partials/weather.handlebars
source=https://basmilius.github.io/weather-icons/production/fill/all
target=src/main/webapp/static/weather

for icon in $(grep -Eo "icon: '[^']+'" $used | cut -d "'" -f 2 | sort | uniq) ; do 
  curl $source/$icon.svg > $target/$icon.svg
done