doc: update priority wording userguide meta

Signed-off-by: jason taylor <jtfas90@gmail.com>

doc/userguide/rules/meta.rst

@@ -161,11 +161,11 @@ All the reference types are defined in the reference.config configuration file.
 priority
 --------
 The priority keyword comes with a mandatory numeric value which can
-range from 1 to 255. The numbers 1 through 4 are most often used.
-Signatures with a higher priority will be examined first. The highest
-priority is 1. Normally signatures have already a priority through
-a classtype definiteion. The classtype definition can be overridden
-with the priority keyword expressed in the signature.
+range from 1 to 255. The values 1 through 4 are commonly used.
+The highest priority is 1. Signatures with a higher priority will
+be examined first. Normally signatures have a priority determined through
+a classtype definition. The classtype definition can be overridden
+by defining the priority keyword in the signature.
 The format of priority is::
 
   priority:1;
@@ -192,4 +192,4 @@ The format is::
 
 If the value is src_ip then the source IP in the generated event (src_ip
 field in JSON) is the target of the attack. If target is set to dest_ip
-then the target is the destination IP in the generated event.
+then the target is the destination IP in the generated event.