Update website links to simpleditor.org

[maxistar]

Motivation

• The public website for the project changed, so in-app and documentation references must point to the new domain https://simpleditor.org.
• Ensure the FAQ link opened from the app and all localized about_message strings reference the correct site.

Description

• Replaced occurrences of https://texteditor.maxistar.me with https://simpleditor.org in the project documentation and resources.
• Updated the README site link in README.md to https://simpleditor.org.
• Updated the app FAQ link in app/src/main/java/com/maxistar/textpad/activities/EditorActivity.java to open https://simpleditor.org/faq/.
• Updated the localized about_message strings in app/src/main/res/values/strings.xml and locale-specific files (values-ar, values-cn, values-de, values-es, values-fr, values-it, values-ja, values-pl, values-pt, values-ru, values-tr, values-uk) to reference the new domain, touching 15 files in total.

Testing

• No automated tests were run for this change.

---

Codex Task