WIP: improved documentation

In WIP state since it is only documentation update

I've also updated some Wiki pages to link to the embedded documentation like:

• The initial guidelines page
• The tutorials page

ci-scripts/doc/ci_dev_home.md

+<table style="border-collapse: collapse; border: none;">
+  <tr style="border-collapse: collapse; border: none;">
+    <td style="border-collapse: collapse; border: none;">
+      <a href="http://www.openairinterface.org/">
+         <img src="../../doc/images/oai_final_logo.png" alt="" border=3 height=50 width=150>
+         </img>
+      </a>
+    </td>
+    <td style="border-collapse: collapse; border: none; vertical-align: center;">
+      <b><font size = "5">OAI CI Dev documentation</font></b>
+    </td>
+  </tr>
+</table>
+
+VM-based RF-Less Environment:
+
+*  [How to setup your test env](./vm_based_simulator_env.md)
+*  [How to deal with OAI source files](./vm_based_simulator_sources.md)
+*  [The main script](./vm_based_simulator_main_scripts.md)
+*  [How to create one or several VM instances](./vm_based_simulator_create.md)
+*  [How to build an OAI variant](./vm_based_simulator_build.md)
+*  [How the build is checked](./vm_based_simulator_check_build.md)
+*  [How to test an OAI variant](./vm_based_simulator_test.md)
+*  [How to destroy all VM instances](./vm_based_simulator_destroy.md)
+
+Currently missing documentation:
+*  How to generate a build report
+*  How to generate a test report
+
+---
+