fix: fs.write instead of stdout

[curbengh]

in some edge case, stdout can be empty when running npm script, i.e. npm run prepare. fs.write is more reliable.

"highlight_alias.json" should be published, it's generated when npm publish. The value in "files" attribute is needed even when "hexo-util": "hexojs/hexo-util", otherwise it would not be generated when npm install.

Address hexojs/hexo#3646 (comment), Address #57 (comment)

How to test

$ rm -r node_modules/

package.json
-  "hexo": "^3.9.0"
+  "hexo": "curbengh/hexo#rc"

$ npm i
$ hexo -v # should be no error
$ npm test

[coveralls]

Coverage remained the same at 95.214% when pulling 975b968 on curbengh:console-fs into 52820ac on hexojs:master.

[curbengh]

I'll es6-fy scripts/build_highlight_alias.js in a separate PR.