Update INSTALL.md

INSTALL.md

@@ -137,14 +137,14 @@ wget https://raw.githubusercontent.com/kaiyou/freeposte.io/master/freeposte.env
 ```
 
 These templates are used for development environment. So, if you do not plan
-on biulding Freeposte.io from source, simply remove the ``build:`` references:
+on building Freeposte.io from source, simply remove the ``build:`` references:
 
 ```
 sed -i '/build:/d' docker-compose.yml
 ```
 
 The default configuration will pull the latest image built from the Docker
-Hub, which is based on the latest commit on Github. This behaviour is ok for
+Hub, which is based on the latest commit on GitHub. This behaviour is ok for
 evaluating Freeposte.io, but you should at least specify a branch. You will
 still get bugfixes and security updates, but breaking changed will not be
 pulled unless you explicitely change the branch number. To specify you want
@@ -219,4 +219,4 @@ You should test all the critical features before using the mail server for
 actual messages. Try to send and receive e-mails, monitor the logs for some
 unexpected errors, etc.
 
-Your server should now be running!
+Your server should now be running!