fix: support multiple paths in pin.add

Author: Alan Shaw

src/pin/add.js

@@ -4,11 +4,12 @@ const CID = require('cids')
 const configure = require('../lib/configure')
 
 module.exports = configure(({ ky }) => {
-  return async (path, options) => {
+  return async (paths, options) => {
+    paths = Array.isArray(paths) ? paths : [paths]
     options = options || {}
 
     const searchParams = new URLSearchParams(options.searchParams)
-    searchParams.set('arg', `${path}`)
+    paths.forEach(path => searchParams.append('arg', `${path}`))
     if (options.recursive != null) searchParams.set('recursive', options.recursive)
 
     const res = await ky.post('pin/add', {