add: Preparation for external posts

Preparation for external blog posts

shared/types/Blog.ts

@@ -0,0 +1,19 @@
+type Post = {
+  url: string
+  title: string
+  excerpt: string
+  date: string
+}
+
+type Author = {
+  name: string
+  img: string
+  img1x: string
+  img2x: string
+  img3x: string
+}
+
+export type ExternalPost = {
+  author: Author
+  posts: Post[]
+}