Add docker-compose config file for better dev environment

CONTRIBUTING.md

@@ -10,6 +10,23 @@ code submission via a merge/pull request is great, but not necessary.
 
 If you encounter any issues with these themes on any devices, please submit a bug report with the device type and a detailed description of what 
 the issue that you're encountering is.
+
+## Run locally
+
+Make sure you have `docker` and `docker-compose` installed on your machine. Then, run the following command:
+
+```bash
+docker-compose up -d
+```
+
+This will start a local server at `http://localhost:4000` where you can see the website.
+
+To watch the server logs, run:
+
+```bash
+docker-compose logs -f
+```
+
 <br /><br />
 
-*Thank you*
+*Thank you*

docker-compose.yml

@@ -0,0 +1,9 @@
+# no version needed since 2020
+
+services:
+  jekyll:
+    image: bretfisher/jekyll-serve
+    volumes:
+      - .:/site
+    ports:
+      - '4000:4000'