typo correction

Signed-off-by: mrgarris0n <gergely.karacsonyi@gmail.com>

Author: mrgarris0n

doc/_admin-guide/020_The_concepts_of_syslog-ng/007_The_structure_of_a_log_message/001_IETF_syslog_messages.md

@@ -8,7 +8,7 @@ description: >-
 
 A syslog message consists of the following parts:
 
-- [[`HEADER`|adm-struct-ietf#the-header-message-part]] (includes the [[PRI|adm-struct-ietf#the-pri-message-part]] as well)
+- [[HEADER|adm-struct-ietf#the-header-message-part]] (includes the [[PRI|adm-struct-ietf#the-pri-message-part]] as well)
 - [[STRUCTURED-DATA|adm-struct-ietf#the-structured-data-message-part]]
 - [[MSG|adm-struct-ietf#the-msg-message-part]]
 

doc/_dev-guide/chapter_8/section_4.md

@@ -3,7 +3,7 @@ title: Filter Function
 id: dev-plugin-dev-filter-func
 ---
 
-This section will guide you through the process of creating a filter function, by going through the files of filter-length, a set of filter functions which filter log messages based on the length of their `${MESSAGE}`. `${MESSAGE}` refers to the {{ site.product.short_name }} macro and not `MSG` as defined by the syslog protocols.
+This section will guide you through the process of creating a filter function, by going through the files of filter-length, a set of filter functions which filter log messages based on the length of their ${MESSAGE}. ${MESSAGE} refers to the {{ site.product.short_name }} macro and not `MSG` as defined by the syslog protocols.
 
 Filter functions are written under `lib/filter/`, and so they do not belong to any module and are not technically plugins. To add a filter function we only need to modify the parser and grammar files; there is no plugin file.