feat(post) : add img to post + fix request to include tags/author

src/app/post/components/post-card/post-card.component.html

src/app/post/components/post-card/post-card.component.scss

src/app/post/components/post-card/post-card.component.ts

src/app/post/components/post-list/post-list.component.html

src/app/post/components/post-list/post-list.component.scss

src/app/post/components/post-list/post-list.component.ts

src/app/post/services/post.service.ts