Site: add Turkish, opened for Turkish browsers

[Talkdedsec]

The project page was English only.

• Every visible text carries its Turkish in a data-tr attribute next to the English (the screenshot alt text too, via data-tr-alt).
• A small inline script switches the page to Turkish for Turkish browsers, adds a TR/EN toggle (top right, hidden without JS) and saves the language only when the visitor uses the toggle.
• English stays the page source, so crawlers and no-JS visitors see English.
• Wording follows README.tr.md (gama tablosu, gece görüşü, renk sıcaklığı); decimals use commas.

Verification

• All 54 texts and the alt text matched an element; the tool refuses to write if any translation matches nothing.
• htmlhint clean.
• Browser: a Turkish browser with nothing saved gets Turkish (title, headings, table, pipeline, alt text); the toggle switches to English, which is saved and survives a reload.