Clarify in the README that healthcheck is only for servers

I also mentioned that it only checks the local server, not others
currently.

Fixes: freeipa#278

Signed-off-by: Rob Crittenden <rcritten@redhat.com>

README.md

@@ -1,8 +1,8 @@
 # What is healthcheck?
 
-It is an attempt to answer the question "Is my IPA installation working properly."
+It is an attempt to answer the question "Is my IPA server installation working properly."
 
-Major pain points in an IPA installation were identified and tests written to verify that the system is configured or running with expected settings.
+Major pain points in an IPA server installation were identified and tests written to verify that the system is configured or running with expected settings.
 
 The major areas currently covered are:
 
@@ -19,6 +19,8 @@ The major areas currently covered are:
 The simplest way to use Healthcheck is to run it from the command-line as root as ipa-healthcheck. Running from the command-line will display the output to the console unless --output-file=FILENAME is used.
 There is output for _all_ tests so we can be sure that an error condition isn't providing a false positive. The command-line option --failures-only will skip printing the SUCCESS conditions. If running in a tty and not using --output-file then --failures-only defaults to True. The --all option will display all output if you want/need it.
 
+Healthcheck is designed only to be run on IPA servers. It only checks for issues on the server it is executed on.
+
 To automate running Healthcheck every day a systemd timer can be used. 
 The default destination directory for healthcheck logs is `/var/log/ipa/healthcheck` and this can be the input into a monitoring system to track changes over time or to alert if a test goes from working to error or warning.