Added remark to make the datasource program executable

datasources/P1-Meter.py

@@ -12,7 +12,7 @@
 # in combination with a rule for "individual program call instead of agent" as described on the official docs of CheckMK:
 # https://docs.checkmk.com/latest/en/datasource_programs.html
 
-# The (this) code should be placed (as cmk user) in ~/local/bin
+# The (this) code should be placed (as cmk user) in ~/local/bin, and made executable (chmod +x filename)
 #
 # The commandline to be used in CheckMK is : this_script_name.py $HOSTADDRESS$