EventEarlyNotification timestamp bugfix and other changes (#84)

This PR fixes EventEarlyNotification timestamp not displaying correctly
and also has some other changes:
- Add xmldocs for `/settingslist`'s `page` option in
SettingsCommandGroup.cs
- Add option description for `index` for `/delreminder`
- Some corrections of grammatical errors in Messages.tt-ru.resx
- Fix `ArgumentOutOfRangeException` in `/settingslist` that appears if
the user uses a negative integer in `page`

---------

Signed-off-by: Macintosh II <95250141+mctaylors@users.noreply.github.com>
Co-authored-by: Octol1ttle <l1ttleofficial@outlook.com>

src/Commands/SettingsCommandGroup.cs

@@ -62,8 +62,9 @@ public class SettingsCommandGroup : CommandGroup
     }
 
     /// <summary>
-    ///     A slash command that lists current per-guild GuildSettings.
+    ///     A slash command that sends a page from the list of current GuildSettings.
     /// </summary>
+    /// <param name="page">The number of the page to send.</param>
     /// <returns>
     ///     A feedback sending result which may or may not have succeeded.
     /// </returns>
@@ -75,7 +76,9 @@ public class SettingsCommandGroup : CommandGroup
     [Description("Shows settings list for this server")]
     [UsedImplicitly]
     public async Task<Result> ExecuteSettingsListAsync(
-        [Description("Settings list page")] int page)
+        [Description("Settings list page")]
+        [MinValue(1)]
+        int page)
     {
         if (!_context.TryGetContextIDs(out var guildId, out _, out _))
         {