update docs

docs/20_Checks/check_ceph_io.md

@@ -9,6 +9,10 @@ It returns a single line for the status and performance data.
 
 * `ceph` binary and sudo permission on it to get the information
 
+```txt
+icingaclient ALL=(ALL) NOPASSWD: /bin/ceph
+```
+
 ## Syntax
 
 ```txt

docs/20_Checks/check_ceph_osd.md

@@ -12,6 +12,10 @@ critical level.
 
 * `ceph` binary and sudo permission on it to get the information
 
+```txt
+icingaclient ALL=(ALL) NOPASSWD: /bin/ceph
+```
+
 ## Syntax
 
 ```txt

docs/20_Checks/check_onehost.md

@@ -27,6 +27,8 @@ v1.1
 
 (c) Institute for Medical Education - University of Bern
 Licence: GNU GPL 3
+
+https://os-docs.iml.unibe.ch/icinga-checks/Checks/check_onehost.html
 ______________________________________________________________________
 
 show count of hosts in OpenNebula and warn if a host is down.