fix: single images being small

Signed-off-by: rooot <[e-mail]>

src/meow.rs

···
                         println!("hehe image ! {}", url);
                         html.push_str(&format!(r#"<meta property="og:image" content="{}">"#, url));
                         html.push('\n');
+
+                        // make sure our image is big !!
+                        html.push_str(
+                            r#"<meta name="twitter:card" content="summary_large_image">"#,
+                        );
+                        html.push('\n');
                     }
                     EmbedMedia::Video(url) => {
                         html.push_str(&format!(r#"<meta property="og:video" content="{}">"#, url));