Small improvements to development dockerfile (#422)

* remove --force-polling from jekyll command
* remove exclude tag from config file for simplicity

Author: DomGarguilo

Dockerfile

@@ -31,4 +31,4 @@ ENV PORT=4000
 EXPOSE $PORT
 
 # Configure the default command to build from the mounted repository.
-CMD bundle exec jekyll serve --force-polling -H $HOST -P $PORT
+CMD bundle exec jekyll serve -H $HOST -P $PORT

_config.yml

@@ -13,7 +13,6 @@ description: > # this means to ignore newlines until "url:"
   The Apache Accumulo™ sorted, distributed key/value store is a robust, scalable,
   high performance data storage and retrieval system.
 url: "https://accumulo.apache.org" # the base hostname & protocol for your site
-exclude: [vendor]
 latest_release: 2.1.2
 javadoc_version: 2.1.2
 num_home_posts: 5