fix typos in the tsp tour visitor documentation

[Becheler]

Before submitting

• This PR targets the develop branch.
• I searched for an existing PR or issue covering the same change.
• My contribution is licensed under the Boost Software License 1.0.

Type of change

• [] Bug fix
• New feature or API addition
• Refactor (no behavior change)
• Documentation
• Build, CI, or tooling
• Other (specify below)

Does this PR introduce a breaking change?

• Yes (describe migration impact below)
• No

What this PR does

Fix old typos that were existing in the html documentation and ported to the antora migration.

See https://www.boost.org/doc/libs/latest/libs/graph/doc/TSPTourVisitor.html

Motivation

Testing

Checklist

• Existing tests pass (b2 in the test/ directory).
• New behavior is covered by a test, or this is a docs / build / refactor change.
• Documentation was updated if user-facing behavior changed.
• No new compiler warnings on the platforms I built against.

[cppalliance-bot]

An automated preview of the documentation is available at https://516.graph.prtest3.cppalliance.org/index.html

If more commits are pushed to the pull request, the docs will rebuild at the same URL.

2026-06-24 09:55:16 UTC

[github-actions]

Compiler-warning counts vs develop (auto-generated).
PR run 28090142660 vs develop run 28012997199 (56f067c129).

Job	Baseline	After	Delta
macos (clang, 14)	44	4	-40
macos (clang, 17)	4	44	+40
macos (clang, 20)	4	44	+40
ubuntu (clang-19, 14)	4	4	0
ubuntu (clang-19, 17)	4	4	0
ubuntu (clang-19, 20)	4	4	0
ubuntu (clang-19, 23)	4	4	0
ubuntu (gcc-14, 14)	10	10	0
ubuntu (gcc-14, 17)	10	10	0
ubuntu (gcc-14, 20)	10	10	0
ubuntu (gcc-14, 23)	10	10	0
windows_msvc_14_3 (msvc-14.3)	971	971	0

[Becheler]

Note about the warning count: the macOS CI jobs use runs-on macos-latest so it lets different jobs/runs land on different Apple clang versions (17 vs 21) with different libc++ deprecation behavior.
So the compiler-warning counts vary non-deterministically and the warning-count bot reports warnings not related to the PR.