Cleanup on dockerfile names

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

README.md

@@ -59,7 +59,14 @@ The OpenAirInterface CN UPF software is composed of the following parts:
 
 <pre>
 openair-cn5g-upf-vpp
-├── ci-scripts:    Directory containing the script files for CI framework.
-└── src:           Source files of UPF.
-    ├── common:    Common header files
+├── build
+│   └── scripts
+├── ci-scripts
+├── docker
+├── docs
+│   └── images
+└── scripts
+    ├── patches
+    ├── tests
+    └── upf_conf
 </pre>

docs/BUILD_IMAGE.md

@@ -20,7 +20,7 @@ Here in our network configuration, we need to pass the "GIT PROXY" configuration
 
 ```bash
 $ docker build --target vpp-upg --tag vpp-upg:develop \
-               --file docker/Dockerfile.ubuntu.18.04 \
+               --file docker/Dockerfile.upf-vpp.ubuntu18 \
                --build-arg NEEDED_GIT_PROXY="http://proxy.eurecom.fr:8080" .
 ```
 
@@ -28,6 +28,6 @@ $ docker build --target vpp-upg --tag vpp-upg:develop \
 
 ```bash
 $ docker build --target vpp-upg --tag vpp-upg:develop \
-               --file docker/Dockerfile.vppupf.rhel7 \
-               --build-arg EURECOM_PROXY="http://proxy.eurecom.fr:8080" .
+               --file docker/Dockerfile.upf-vpp.rhel7 \
+               --build-arg NEEDED_GIT_PROXY="http://proxy.eurecom.fr:8080" .
 ```