Add README.md under container

Add README.md to introduce docker images under container directory as well as how to build docker images.

Signed-off-by: Hao, Ruomeng <ruomeng.hao@intel.com>

container/README.md

@@ -0,0 +1,63 @@
+# Docker Image Builder
+
+There are several docker image files in the sub directories of current directory. Each sub directory contains Dockerfile of an image. Please find description of each image as follows.
+
+|  Sub directory | Image name  | Description  | 
+|---|---|---|
+|  ccnp-device-plugin | ccnp-device-plugin  | CCNP Device plugin |
+|  ccnp-eventlog-server | ccnp-eventlog-server | Eventlog server |
+|  ccnp-measurement-server | ccnp-measurement-server  | Measurement server |
+|  ccnp-quote-server | ccnp-quote-server  | Quote server |
+|  ccnp-node-measurement-example | ccnp-node-measurement-example  | Example image of getting eventlog and measurement using CCNP SDK |
+|  pccs | pccs  | PCCS docker image for Intel® TDX remote attestation. Not required for CCNP usage.|
+|  qgs | qgs  | QGS docker image for Intel® TDX remote attestation. Not required for CCNP usage. |
+
+
+### Build Docker images
+
+`build.sh` is a tool to build all above images and push them to a user-specified image registry. It supports below parameters for different use scenarios.
+
+|  Parameter | Description  | Options  | Default Value  | Required\|Optional  |
+|---|---|---|---|---|
+|  -a | Action the script will execute: `all` means build and publish images; `build` means build images only; `publish` means publish images; `save` means docker save images to local file.  | build\|publish\|save\|all  | all  | Optional  |
+|  -r |  Image registry. Images will be pushed to this image registry. |   |   | Required  |
+|  -c | Image name to build. Image names will be the same as sub directory names under directory `container`. By default it will be `all` meaning build all images under `container` | Sub directory name under directory `container`.  |  all |  Optional |
+|  -g | Image tag  |   |  latest |  Optional |
+|  -f | Flag to build images with parameter "--no-cache"  |   |  |  Optional |
+|  -p | Flag to build pccs docker image. Building pccs docker image requires interactive configuration. Please refer to [README.md](../container/pccs/README.md).  |   |   |  Optional |
+|  -q | Flag to build qgs docker image. Please refer to [README.md](../container/qgs/README.md).  |  |   |  Optional |
+|  -h | Show this usage guide.  |  |   |  Optional |
+
+_NOTE: The script need to run on a server with docker installed._
+
+_NOTE: please set `HTTP_PROXY`, `HTTPS_PROXY`, `NO_PROXY` in docker daemon if they are needed. Please refer to [Configure the Docker daemon to use a proxy server](https://docs.docker.com/config/daemon/systemd/#httphttps-proxy)._
+
+Below are usage examples for different scenarios. Please replace the parameters with your input.
+
+```
+# Build all CCNP images with tag 0.3 and push them to remote registry test-registry.intel.com
+$ sudo ./build.sh -r test-registry.intel.com/test -g 0.3
+
+# Build images only with tag 0.3
+$ sudo ./build.sh -a build -g 0.3
+
+# Build ccnp-measurement-server image with tag 0.3 and push them to remote registry test-registry.intel.com
+$ sudo ./build.sh -c ccnp-measurement-server -r test-registry.intel.com/test -g 0.3
+
+# Build pccs image with tag 0.3 and push it to remote registry test-registry.intel.com
+$ sudo ./build.sh -c pccs -r test-registry.intel.com/test -g 0.3 -p
+
+# Build qgs image with tag 0.3 and push it to remote registry test-registry.intel.com
+$ sudo ./build.sh -c qgs -r test-registry.intel.com/test -g 0.3 -q
+```
+
+After the script is successful, it's supposed to see corresponding CCNP docker images.
+
+```
+$ sudo docker images
+ccnp-node-measurement-example   <your image tag>
+ccnp-eventlog-server            <your image tag>
+ccnp-measurement-server         <your image tag>
+ccnp-quote-server               <your image tag>
+ccnp-device-plugin              <your image tag>
+```