Improved printing support

In the printed version of each page/post

- Scaled down the screenshots
- Included the date and my name

Author: VincentTam

sass/custom/_print.scss

@@ -62,6 +62,11 @@ a.basic-alignment {
     display: none !important;
 }
 
+img {
+    max-width: 100%;
+    height: auto;
+}
+
 .github-fork-ribbon-wrapper {
     display: none !important;
 }