Make return value of LinkifyIt.match nullable (#29810)

types/linkify-it/index.d.ts

@@ -45,7 +45,7 @@ declare namespace LinkifyIt {
 
     interface LinkifyIt {
         add(schema: string, rule: Rule): LinkifyIt;
-        match(text: string): Match[];
+        match(text: string): Match[] | null;
         normalize(raw: string): string;
         pretest(text: string): boolean;
         set(options: Options): LinkifyIt;

types/linkify-it/linkify-it-tests.ts

@@ -30,7 +30,9 @@ linkifier
 const matches = linkifier.match(
     "https://github.com/DefinitelyTyped/DefinitelyTyped/"
 );
-matches.forEach(({ index, lastIndex, raw, schema, text, url }) => {});
+if (matches !== null) {
+    matches.forEach(({ index, lastIndex, raw, schema, text, url }) => {});
+}
 
 // complex rule
 linkifier.add("@", {