release 0.15.13

[forrestguice]

• adds app options to show daylight comparison (today/tomorrow) (closes Add day length difference from the day before and fix minute symbol #773).
• increases the maximum before/after alarm offset (closes [Feature request] Longer Before/After Offset Window #779); fixes localization of display values.
• fixes app crash when launching the app after using "restore backup" (closes Crash when opening app: ClassCastException: String cannot be cast to Long #783).
• replaces links to "online help" and improves help presentation; the app's website is now hosted on Codeberg (https://forrestguice.codeberg.page/Suntimes/) (mirror project to Codeberg #629).
• now mirroring git repository to Codeberg (https://codeberg.org/forrestguice/Suntimes) (mirror project to Codeberg #629).