v0.2.0: fix leaked multi-line {# #} comments, add German translation

- Fix template comments rendering as literal text: Django's {# #} tag
  regex (tag_re in django/template/base.py) has no re.DOTALL, so a
  comment spanning multiple lines is never recognized as a tag at all
  and leaks into the rendered output verbatim - exactly what showed up
  under "Elevation". Collapsed all three offending comments to single
  lines. This was also almost certainly the real cause of the "PNG
  could not be generated" report: two of the leaked comments sat
  inside the shared SVG partial, corrupting the exported SVG enough
  that the browser's image decoder rejected it (my own onerror handler
  then showed a misleading CORS-sounding message - the actual bug was
  malformed markup, not cross-origin images).
- Add a German translation (locale/de/), built from every _() and
  {% trans %}/{% blocktrans %} string in the plugin (269 entries,
  cross-checked against the source for completeness). English needs no
  catalog of its own since it's the literal source text; both were
  already listed in NetBox's own language selector.
- Add CHANGELOG.md and bump the version to 0.2.0, covering this and
  every unreleased change so far; will keep bumping per change from
  here on.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "netbox-rack-concept"
-version = "0.1.0"
+version = "0.2.0"
 description = "Rack blueprints for NetBox: plan racks and their equipment without creating real racks or devices"
 readme = "README.md"
 requires-python = ">=3.12"
@@ -28,4 +28,6 @@ netbox_rack_concept = [
     "templates/netbox_rack_concept/*.html",
     "templates/netbox_rack_concept/inc/*.html",
     "static/netbox_rack_concept/*",
+    "locale/*/LC_MESSAGES/*.po",
+    "locale/*/LC_MESSAGES/*.mo",
 ]