Rename `contributing/samples/plugin/` to `contributing/samples/plugins/` so the
samples directory matches the `plugins/` naming already used everywhere else in
the repository for this feature area: the `google.adk.plugins` source package
(`src/google/adk/plugins/`), the guide at `docs/guides/plugins/`, and the unit
tests at `tests/unittests/plugins/`. It also matches the plural naming used by
every sibling sample group (`tools/`, `models/`, `workflows/`, `patterns/`, and
others). The moved files themselves are unchanged.
Also update the paths that pointed into the renamed directory:
- Repoint the two "Related samples" links in the reflect-and-retry tool plugin
guide, which the move would otherwise break.
- Fix the run commands in the two sample READMEs and in the debug logging agent
docstring. These already omitted the grouping directory and so did not work
before the rename either; they now refer to paths that exist.
Co-authored-by: Jason Zhang <jasoncz@google.com>
PiperOrigin-RevId: 960009471
George Weale