docs: fix typos and improve documentation consistency (#27418)

docs/development/best-practices.md

docs/development/zod.md

docs/usage/configuration-options.md

docs/usage/getting-started/private-packages.md

docs/usage/key-concepts/pull-requests.md

docs/usage/self-hosted-configuration.md

docs/usage/self-hosted-experimental.md

docs/usage/troubleshooting.md