fix: swap @yields for @returns (#178)

Motivation:
* Fix ipfs/js-ipfs#4080
* tl;dr
  * fix `import globSourceImport from 'ipfs-utils/src/files/glob-source.js'` from typescript
  * fix importing ipfs-core from typescript

Context:
* microsoft/TypeScript#23857

Strategy
* Use jsdoc `@return` instead of `@yields` because tsc doesn't understand that `@yields` implies a `@return` type

Test Case
* gobengo/ipfs-core-esm-test#3
* I tested locally with `npm link` and this seemed to fix it

Author: gobengo

src/files/glob-source.js

@@ -18,7 +18,12 @@ const errCode = require('err-code')
  * @param {boolean} [options.preserveMtime] - preserve mtime
  * @param {number} [options.mode] - mode to use - if preserveMode is true this will be ignored
  * @param {import('ipfs-unixfs').MtimeLike} [options.mtime] - mtime to use - if preserveMtime is true this will be ignored
- * @yields {Object} File objects in the form `{ path: String, content: AsyncIterator<Buffer> }`
+ * @returns {AsyncGenerator<{
+ * path: string;
+ * content: AsyncIterable<Buffer> | undefined;
+ * mode: number | undefined;
+ * mtime: import("ipfs-unixfs/types/src/types").MtimeLike | undefined;
+ * }, void, unknown>} File objects that match glob
  */
 module.exports = async function * globSource (cwd, pattern, options) {
   options = options || {}