Add showcase teaser images

Author: deccer

blog/2020/2020-10-31-showcase-2020-10/index.md

@@ -8,6 +8,7 @@ tags: ['showcase', 'showcase-2020']
 ---
 
 October 2020 showcase
+![](https://imgur.com/PbW17p5.jpg)
 <!-- truncate -->
 
 ![](https://imgur.com/OAgojJD.jpg)

blog/2020/2020-11-30-showcase-2020-11/index.md

@@ -8,6 +8,7 @@ tags: ['showcase', 'showcase-2020']
 ---
 
 November 2020 showcase
+![](https://imgur.com/7Dqp5bE.jpg)
 <!-- truncate -->
 
 ![](https://imgur.com/jLL020P.jpg)

blog/2020/2020-12-31-showcase-2020-12/index.md

@@ -8,6 +8,7 @@ tags: ['showcase', 'showcase-2020']
 ---
 
 December 2020 showcase
+![](https://imgur.com/xPcGGVf.jpg)
 <!-- truncate -->
 
 ![](https://imgur.com/Rt82xH4.png)

blog/2021/2021-01-01-showcase-best-of-2020/index.md

@@ -8,6 +8,8 @@ tags: ['showcase', 'showcase-2020']
 ---
 
 Best of 2020 Community Creation Showcase
+![](https://i.imgur.com/Jken5mH.png)
+
 <!-- truncate -->
 
 ![](https://i.imgur.com/wCchteK.png)