feat: LiquidOptions.dateFormat to override default date format (#587)

doc: updates related to LiquidOptions.dateFormat
doc: revamped the date filter doc for easier reference

src/liquid-options.ts

@@ -38,6 +38,8 @@ export interface LiquidOptions {
   lenientIf?: boolean;
   /** JavaScript timezone name or timezoneOffset for `date` filter, default to local time. That means if you're in Australia (UTC+10), it'll default to `-600` or `Australia/Lindeman` */
   timezoneOffset?: number | string;
+  /** Default date format to use if the date filter doesn't include a format. Defaults to `%A, %B %-e, %Y at %-l:%M %P %z`. */
+  dateFormat?: string;
   /** Strip blank characters (including ` `, `\t`, and `\r`) from the right of tags (`{% %}`) until `\n` (inclusive). Defaults to `false`. */
   trimTagRight?: boolean;
   /** Similar to `trimTagRight`, whereas the `\n` is exclusive. Defaults to `false`. See Whitespace Control for details. */