updating README

Signed-off-by: Nick Chappell <nick@intronic.org>

Merged from PR #34: https://github.com/Icinga/puppet-icinga2/pull/34
+ Adding notificationcommand object

Signed-off-by: Nick Chappell <nick@intronic.org>

Merged in from: https://github.com/Icinga/puppet-icinga2/pull/32

refs#7228: https://dev.icinga.org/issues/7228
* fixed typos and mistakes. thanks nickchappell.

Signed-off-by: Nick Chappell <nick@intronic.org>

Merged in from: https://github.com/Icinga/puppet-icinga2/pull/32

refs#7228: https://dev.icinga.org/issues/7228
* fixed validation

Signed-off-by: Nick Chappell <nick@intronic.org>

Merged in from: https://github.com/Icinga/puppet-icinga2/pull/32

refs#7228: https://dev.icinga.org/issues/7228
added default value to arguments, env and vars and moved check to the template.

Signed-off-by: Nick Chappell <nick@intronic.org>

Merged in from: https://github.com/Icinga/puppet-icinga2/pull/32

refs#7228: https://dev.icinga.org/issues/7228
Merge branch 'master' of git.icinga.org:puppet-icinga2
Add a EventCommand object defined type, refs#7215

Signed-off-by: Nick Chappell <nick@intronic.org>

Merged in from: https://github.com/Icinga/puppet-icinga2/pull/33

refs#7215: https://dev.icinga.org/issues/7215
* fixed typos, changed default values and changed parameters validation.

Signed-off-by: Nick Chappell <nick@intronic.org>

Merged in from: https://github.com/Icinga/puppet-icinga2/pull/33

refs#7215: https://dev.icinga.org/issues/7215
* fixed eventcommand example

Signed-off-by: Nick Chappell <nick@intronic.org>

Merged in from: https://github.com/Icinga/puppet-icinga2/pull/33

refs#7215: https://dev.icinga.org/issues/7215
added default value to arguments, env and vars and moved check to the template.

Signed-off-by: Nick Chappell <nick@intronic.org>

Merged in from: https://github.com/Icinga/puppet-icinga2/pull/33

refs#7215: https://dev.icinga.org/issues/7215