Add a generic section on how to mount extra data into our images

We regularly get questions about how to add binaries or other files into our images at runtime.
There are a few options that we recommend and it differs per operator because not all of them support extra_volumes, but we never wrote this down in a structured fashion and picked a recommended option.

Lets add a section to the docs and spell out the main three or four options along with pros and cons and also mention what not to do.

Possible ways:

• mount OCI artifact
• copy to PV and mount that
• init container to download and copy
• gitsync

Not recommended:

• stick binary data into a ConfigMap or Secret

適切な共有ドキュメントセクションを特定し、既存の operator ページでランタイムデータと volume オプションがどのように説明されているかを確認します。OCI artifacts、persistent volume へのコピー、init container、gitsync を扱う構造化されたセクションを追加し、それぞれの利点と欠点、およびバイナリデータを ConfigMaps や Secrets に置かないよう警告する内容を含めます。