hyprlock: add timezone documentation (#921)

pages/Hypr Ecosystem/hyprlock.md

@@ -379,6 +379,7 @@ Worth noting:
 - label can be forcefully updated by specifying `update:<time>:1` or `update:<time>:true` and sending `SIGUSR2` to hyprlock. `<time>` can be `0` in this case.
 - `$ATTEMPTS[<string>]` format can be used to show `<string>` when there are no failed attempts. You can use pango-markup here. `<string>` can be empty to hide.
 - `$LAYOUT[<str0>,<str1>,...]` format is available to replace indexed layouts. You can use settings from `hyprland.conf`, e.g. `$LAYOUT[en,ru,de]`. Also, single `!` character will hide layout. E.g. `$LAYOUT[!]` will hide default (0 indexed) and show others.
+- `$TIME` and `$TIME12` will use timezone from TZ environment variable. If it's not set, system timezone will be used, falling back to UTC in case of errors.
 - Variables seen above are parsed _before_ the command is ran.
 - **do not** run commands that never exit. This will hang the AsyncResourceGatherer and you won't have a good time.