Add file with short experiment description (not needed in theory since everything can be retrieved from the git history, but still useful

exps.txt

@@ -0,0 +1,4 @@
+E000 -- standard run as coming from the ecearth_patch
+	3.3.0, rev 6607, from scratch, standard output
+E001 -- with new output, constant forcing
+E002 -- restarting from David Docquier's EC05 rebuilt restarts