DOC: adding table of content

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

docker/README.md

@@ -14,7 +14,14 @@
 
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-to be done
+**Table of Contents**
+
+1. [Build Strategy](#1-build-strategy)
+2. [File organization](#2-file-organization)
+3. [Building using docker under Ubuntu 18.04](#3-building-using-docker-under-ubuntu-1804)
+4. [Building using podman under Red Hat Entreprise Linux 8.2](#4-building-using-podman-under-red-hat-entreprise-linux-82)
+5. [Running modems using docker under Ubuntu 18.04](#5-running-modems-using-docker-under-ubuntu-1804)
+6. [Running modems using podman under Red Hat Entreprise Linux 8.2](#6-running-modems-using-podman-under-red-hat-entreprise-linux-82)
 
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