[chore] - remove unused imports

Author: cscheid

src/core/markdown-pipeline.ts

@@ -3,10 +3,8 @@
  *
  * Copyright (C) 2020-2022 Posit Software, PBC
  */
-import { base } from "acorn/walk";
 import { decodeBase64, encodeBase64 } from "encoding/base64";
 import { Document, Element, Node } from "./deno-dom.ts";
-import { decode } from "https://deno.land/[email protected]/encoding/base64.ts";
 
 export interface PipelineMarkdown {
   blocks?: Record<string, string>;