Updates docs

Author: lindseywild

README.md

@@ -80,7 +80,7 @@ So, a relative date phrase is used for up to a month and then the actual date is
 | `month`        | `month`          | `'numeric'\|'2-digit'\|'short'\|'long'\|'narrow'\|undefined`                                | <sup>***</sup>                   |
 | `year`         | `year`           | `'numeric'\|'2-digit'\|undefined`                                                           | <sup>****</sup>                  |
 | `timeZoneName` | `time-zone-name` | `'long'\|'short'\|'shortOffset'\|'longOffset'` `\|'shortGeneric'\|'longGeneric'\|undefined` | `undefined`                      |
-| `noTitle`      | `no-title`       | `'boolean \| null'`                                                                         | -                                |
+| `noTitle`      | `no-title`       | `'boolean \| undefined'`                                                                    | `undefined`                      |
 
 <sup>*</sup>: If unspecified, `formatStyle` will return `'narrow'` if `format` is `'elapsed'` or `'micro'`, `'short'` if the format is `'relative'` or `'datetime'`, otherwise it will be `'long'`.
 

src/relative-time-element.ts

@@ -387,7 +387,7 @@ export class RelativeTimeElement extends HTMLElement implements Intl.DateTimeFor
     return this.hasAttribute('no-title')
   }
 
-  set noTitle(value: boolean | null) {
+  set noTitle(value: boolean | undefined) {
     this.setAttribute('no-title', value?.toString() || '')
   }