Add explanation about the configuration file format

misc/graylog.conf

@@ -1,3 +1,47 @@
+############################
+# GRAYLOG CONFIGURATION FILE
+############################
+#
+# This is the Graylog configuration file. The file has to use ISO 8859-1/Latin-1 character encoding.
+# Characters that cannot be directly represented in this encoding can be written using Unicode escapes
+# as defined in https://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#jls-3.3, using the \u prefix.
+# For example, \u002c.
+# 
+# * Entries are generally expected to be a single line of the form, one of the following:
+#
+# propertyName=propertyValue
+# propertyName:propertyValue
+#
+# * White space that appears between the property name and property value is ignored,
+#   so the following are equivalent:
+# 
+# name=Stephen
+# name = Stephen
+#
+# * White space at the beginning of the line is also ignored.
+#
+# * Lines that start with the comment characters ! or # are ignored. Blank lines are also ignored.
+#
+# * The property value is generally terminated by the end of the line. White space following the
+#   property value is not ignored, and is treated as part of the property value.
+#
+# * A property value can span several lines if each line is terminated by a backslash (‘\’) character.
+#   For example:
+#
+# targetCities=\
+#         Detroit,\
+#         Chicago,\
+#         Los Angeles
+#
+#   This is equivalent to targetCities=Detroit,Chicago,Los Angeles (white space at the beginning of lines is ignored).
+# 
+# * The characters newline, carriage return, and tab can be inserted with characters \n, \r, and \t, respectively.
+# 
+# * The backslash character must be escaped as a double backslash. For example:
+# 
+# path=c:\\docs\\doc1
+#
+
 # If you are running more than one instances of Graylog server you have to select one of these
 # instances as master. The master will perform some periodical tasks that non-masters won't perform.
 is_master = true