Update tools/create-translation-issues.sh with primary references to weblate

**What is the current behaviour and why should it be changed?**

Currently there's in my opinion too much focus on the manual approach. This should be updated.

**Describe possible approaches**
Reword the translation issue template in the script. Suggestions welcome.

**Has this feature been discussed and generally agreed?**
No

Inspect tools/create-translation-issues.sh, especially the translation issue template and its references to the manual workflow. Confirm the intended Weblate-first wording with maintainers, then update the template so Weblate is the primary reference and the manual approach is secondary.

Written by the indexing model from the issue text.