Community-Lab introduction

Modified script.txt from [bba21f47ef] to [e43490b60d].

   107    107   - A slice is a management concept that groups a set of related slivers.
   108    108   - A sliver holds the resources (CPU, memory, disk, bandwidth, interfaces…)
   109    109     allocated for a slice in a given node.
   110    110   - A node hosts several slivers at the same time. *##*
   111    111   
   112    112   ** Node architecture
   113    113   allows the realization of these concepts.  *##* A node consists of a CD, a RD
   114         -and a rD on a wired local network. *##*
          114  +and a rD connected to the same wired local network. *##*
   115    115   
   116    116   - The community device
   117    117     - Completely normal CN device, so existing ones can be used.
   118    118     - routes traffic between the CN and the local network (which runs no routing
   119    119       protocol). *##*
   120    120   - The research device
   121    121     - Usually more powerful than CD, since experiments run here.