docs: Add README file with some tips regarding G5K

Author: roda82

README.md

@@ -0,0 +1,23 @@
+# Tips G5k
+
+- To execute a script on a given list of servers (chifflot) during 4 hours max: 
+
+```
+oarsub -l {"host in ('chifflot-1.lille.grid5000.fr','chifflot-4.lille.grid5000.fr','chifflot-5.lille.grid5000.fr')"}/host=1,walltime=4 ./my_script.sh
+```
+
+- To check usage policy: 
+
+```
+usagepolicycheck -t
+```
+
+- To install docker : 
+
+```
+g5k-setup-docker -t
+``` 
+
+- To check reservation at Lille: 
+
+https://intranet.grid5000.fr/oar/Lille/monika.cgi