Admin can now write posts

Posts can be displayed on the website. Subscribers are automatically
notified by email. This gives the opportunity to track explicitly how
many people followed the link provided in the emails sent without being
intrusive (no invisible image).

src/routes/admin.rs

@@ -2,6 +2,7 @@ mod change_password;
 mod dashboard;
 mod logout;
 mod newsletters;
+mod posts;
 
 use crate::{routes::error_chain_fmt, templates::ErrorTemplate};
 use askama::Template;
@@ -14,6 +15,7 @@ pub use change_password::*;
 pub use dashboard::*;
 pub use logout::*;
 pub use newsletters::*;
+pub use posts::*;
 use reqwest::StatusCode;
 
 #[derive(thiserror::Error)]