Add AudiobookCovers.com metadata provider

AudiobookCovers.com acts as a cover-only metadata provider, therefore will only show up in the covers selector.

server/providers/AudiobookCovers.js

@@ -0,0 +1,26 @@
+const axios = require('axios')
+const Logger = require('../Logger')
+
+class AudiobookCovers {
+  constructor() { }
+
+  async search(search) {
+    const url = `https://api.audiobookcovers.com/cover/bytext/`
+    const params = new URLSearchParams([['q', search]])
+    const items = await axios.get(url, { params }).then((res) => {
+      if (!res || !res.data) return []
+      return res.data
+    }).catch(error => {
+      Logger.error('[AudiobookCovers] Cover search error', error)
+      return []
+    })
+    // console.log(items)
+    // return items as an array of objects, each object contains:
+    // cover: item.filename
+    return items.map(item => { return { cover: item.filename } })
+  }
+}
+
+
+
+module.exports = AudiobookCovers