Maint: Improve example tagmail.conf file with comments

conf/tagmail.conf

@@ -1 +1,16 @@
-all: [email protected]
+# tagmail.conf
+
+# This file configures the `tagmail` report, which can be enabled by including
+# tagmail in the puppet master's `reports` setting. (`reports = https, tagmail`)
+
+# Each line in this file should consist of a comma-separated list of tags and/or
+# negated tags (`!tag`), a colon, and a comma-separated list of email addresses.
+# The `all` psuedo-tag will email all log events.
+# See http://docs.puppetlabs.com/guides/configuring.html#tagmailconf for
+# a complete description of this file.
+
+# Example:
+
+# all: [email protected]
+# webserver, !mailserver: [email protected]
+# emerg, crit: [email protected], [email protected], [email protected]