Manually add an editorial article of u.i.

We want to test how SNS creates tags on our own editorial articles. These tags will be used to guide the website development. Here, we just use an abstract of an article that is going to be published on umwelt.info at the end of the year. Additionally, we created a tag within Wasserportal Berlin-entries, which can be used with !530 (merged) to search for related entries of Wasserportal Berlin.