update README and Dockerfile to reflect corrected release process

Author: andrewsg

README.md

@@ -73,8 +73,10 @@ repository.
 - Copy the resulting tar.gz file to your application's folder, in the same
 directory as the Dockerfile.
 - Edit the Dockerfile in your application and look for the line that says
-`COPY (...) /home/vmagent/python-runtime.tar.gz`
-- Replace the URL in that line with the filename of your generated tar.gz file.
+`ADD (...) /home/vmagent/python-runtime.tar.gz`
+- Replace that line with a COPY command, with the filename of your generated
+tar.gz file instead of the URL as the source, and the same destination. An
+example is included in the Dockerfile comments.
 - Deploy your application. A warning during deployment where your tar.gz file is
 rejected for addition because it is too large can be ignored.
 

multicore_runtime/dev/Dockerfile

@@ -5,7 +5,11 @@ RUN apt-get -q update && \
     python2.7 python-pip python-gevent python-greenlet && \
   apt-get clean && rm /var/lib/apt/lists/*_*
 
-COPY https://github.com/GoogleCloudPlatform/appengine-python-vm-runtime/releases/download/0.1/python-runtime-0.1.tar.gz /home/vmagent/python-runtime.tar.gz
+ADD https://github.com/GoogleCloudPlatform/appengine-python-vm-runtime/releases/download/v0.1/appengine-python-vm-runtime-0.1.tar.gz /home/vmagent/python-runtime.tar.gz
+
+# To use a custom-built version of the runtime, comment out the above ADD
+# command and instead use the following line:
+# COPY appengine-python-vm-runtime-0.1.tar.gz /home/vmagent/python-runtime.tar.gz
 
 RUN pip install --upgrade pip>=6.1.1 gunicorn==19.1.1
 RUN pip install /home/vmagent/python-runtime.tar.gz