fix figure width for smaller images

fixes #514

issue reported by @vlvk

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+
+indent_size = 2
+indent_style = space

assets/css/terminal.css

@@ -211,6 +211,10 @@ img {
   overflow: hidden;
 }
 
+figure {
+  width: fit-content;
+}
+
 figure img,
 figure video {
   margin-bottom: 0;