message: Add warn function
diff: @@ -7,7 +7,7 @@ import {
  } from "../deps/markdown_it.ts";
  import loader from "../core/loaders/text.ts";
  import Markdown from "../core/engines/markdown.ts";
  -import { merge } from "../core/utils.ts";
  +import { merge, warn } from "../core/utils.ts";
  import { posix } from "../deps/path.ts";
  export interface Options {
  @@ -117,7 +117,7 @@ function createMarkdown(site: Site, options: Options) {
  try {
  return site.url(`~/${file}`);
  } catch {
  - // Ignored
  + warn("markdown", `Could not resolve link "${link}"`, { filename });
  }
  }
  