Add excepts for all posts

_posts/2020/08/2020-08-25-getting-started-with-docker-1.md

@@ -11,6 +11,9 @@ tags:
     - consulting
     - docker
 excerpt: >
+    Understanding Docker probably won't solve all of your problems,
+    but it can be a really useful tool when trying to build reproducible software that will run almost anywhere.
+    In this series of blog posts, we will explore how to setup and use Docker for scientific applications.
 ---
 
 {:.summary}

_posts/2020/08/2020-08-25-getting-started-with-docker-2.md

@@ -11,7 +11,8 @@ tags:
   - consulting
   - docker
 excerpt: >
-    
+    Previously, we learned about Docker, and how to run other people's Docker containers.
+    In this post, we will explore building our own images to package up our projects.
 ---
 
 {:.summary}

_posts/2020/08/2020-08-25-getting-started-with-docker-3.md

@@ -11,6 +11,9 @@ tags:
     - consulting
     - docker
 excerpt: >
+    The final part in the "Getting Started with Docker" series:
+    Having explored how to use Docker in a general sense,
+    we will look at how Docker can be used practically in your day-to-day scientific work.
 ---
 
 {:.summary}