Disabled host volume for edxapp

The settings have not yet been merged. The host volume should only be used if the local repository has been rebased on the branch in https://github.com/edx/edx-platform/pull/14376.

ECOM-6634

Author: Clinton Blackburn

README.md

@@ -63,3 +63,4 @@ There is still work to be done before this is ready for full release to the Open
 2. Finish provisioning all services
 3. Load demo data
 4. PyCharm debugging
+5. Merge devstack settings for edxapp (https://github.com/edx/edx-platform/pull/14376), and reactivate host volume

docker-compose.yml

@@ -107,8 +107,8 @@ services:
     ports:
       - "18000:18000"
       - "18010:18010"
-    volumes:
-      - ../edx-platform:/edx/app/edxapp/edx-platform
+#    volumes:
+#      - ../edx-platform:/edx/app/edxapp/edx-platform
 
   programs:
     command: /edx/app/programs/devstack.sh start