docs: validate with mkdocs (#30735)

.eslintignore

.github/workflows/build.yml

.gitignore

.ls-lint.yml

.markdownlint-cli2.jsonc

.prettierignore

.python-version

.vscode/settings.json

docs/usage/assets/css/style.css

package.json

pdm.lock

pyproject.toml

tools/docs/index.ts

tools/mkdocs.ts

tools/mkdocs/.gitignore

tools/mkdocs/includes/abbreviations.md

tools/mkdocs/mkdocs-hooks/custom-edit-url.py

tools/mkdocs/mkdocs.yml

tools/mkdocs/overrides/main.html

tools/utils/exec.ts