Make the documented -v example match what black actually prints

[ump45nose]

Description

The -v/--verbose example in docs/usage_and_configuration/the_basics.md shows two lines that don't match what the CLI actually prints:

1. Using configuration from /tmp/pyproject.toml. — when the config file is auto-discovered (no --config passed, which is the case in the shown command black src/ -v), main prints Using configuration from project root. (src/black/__init__.py:660-664, the ParameterSource.DEFAULT branch). The message that names the file is spelled Using configuration in '<path>'. and only appears when --config is passed explicitly. So the shown line can never be printed by the shown command.
2. The summary line ends without a period. get_summary_message always appends a final "." (src/black/report.py:122), and the other summary examples in the same file already end with a period (e.g. line 472).

Two one-token fixes inside the existing fenced block; no prose changes.

Checklist - did you ...

• Implement any code style changes under the --preview style, following the stability policy? — not applicable (docs only, ticked to show the checklist was read)
• Add an entry in CHANGES.md if necessary? — not necessary (docs-only; happy to have the skip-changelog label applied)
• Add / update tests if necessary? — not necessary (no behavior change; no test toolchain available in this environment, and the fix is verified by reading the message-producing code at the base commit)
• Add new / update outdated documentation? — this PR is the documentation fix

Verification: docs-only; each claim checked against src/black/__init__.py and src/black/report.py at base commit 11cff13. My open PRs #5555 and #5556 edit other line ranges of this same file (quickstart --version example and the INTERNAL ERROR example); the hunks here are disjoint from both.