Allow the creation of new entries

src/backends/backend.js

@@ -1,6 +1,7 @@
 import TestRepoBackend from './test-repo/implementation';
 import GitHubBackend from './github/implementation';
 import { resolveFormat } from '../formats/formats';
+import { createEntry } from '../valueObjects/Entry';
 
 class LocalStorageAuthStore {
   storageKey = 'nf-cms-user';
@@ -57,6 +58,11 @@ class Backend {
     return this.implementation.entry(collection, slug).then(this.entryWithFormat(collection));
   }
 
+  newEntry(collection) {
+    const newEntry = createEntry();
+    return this.entryWithFormat(collection)(newEntry);
+  }
+
   entryWithFormat(collection) {
     return (entry) => {
       const format = resolveFormat(collection, entry);