Add a German README translation — checking conventions first

[flitzrrr]

Summary

I'd like to contribute a German translation of the README. Since the repo has no localized READMEs yet, I want to confirm conventions before investing in the translation.

Context

• README.md is currently English-only (~58 KB). No docs/ localization, no other language versions.
• I checked: no existing open or closed PR/issue for a translation.
• The repo is MIT-licensed with a "PRs Welcome" badge, so contributions are clearly accepted in principle — this issue is only about the localization convention.

Questions for the maintainers

1. Is a German README translation welcome, or do you want to keep the docs English-only for now?
2. If welcome, which filename/layout do you prefer? Common patterns are:
   • README.de.md at the repo root
   • README-DE.md at the repo root
   • docs/de/README.md
3. The README is large (~58 KB). Should a first translation cover the whole document, or would you prefer a scoped subset (e.g. down to a specific section) as a starting point?
4. Any terminology that must stay in English (agent names, "The Agency" branding, deliverable names)?

I'll open the PR once conventions are confirmed. Thanks for agency-agents.