Resolve "Improve artist/playlist images display"

Closes #25 (closed)

public/css/styles.css

+@charset "UTF-8";
+
+.spotify-image {
+  display: inline-block;
+  text-align: center;
+  justify-content: center;
+  align-items: center;
+  height: 1rem;
+  width: 1rem;
+  max-height: 1rem;
+  max-width: 1rem;
+}
+
+.spotify-image>img {
+  border: solid 1px #888;
+  text-align: center;
+  max-height: 1rem;
+  max-width: 1rem;
+  margin: auto;
+}