Change doc/ subdir into a git submodule

The docs now live at https://github.com/zeek/zeek-docs

doc/scripts/policy/protocols/dns/auth-addl.bro.rst

@@ -1,28 +0,0 @@
-:tocdepth: 3
-
-policy/protocols/dns/auth-addl.bro
-==================================
-.. bro:namespace:: DNS
-
-This script adds authoritative and additional responses for the current
-query to the DNS log.  It can cause severe overhead due to the need
-for all authoritative and additional responses to have events generated.
-This script is not recommended for use on heavily loaded links.
-
-:Namespace: DNS
-:Imports: :doc:`base/protocols/dns/main.bro </scripts/base/protocols/dns/main.bro>`
-
-Summary
-~~~~~~~
-Redefinitions
-#############
-================================================================ =
-:bro:type:`DNS::Info`: :bro:type:`record`                        
-:bro:id:`dns_skip_all_addl`: :bro:type:`bool` :bro:attr:`&redef` 
-:bro:id:`dns_skip_all_auth`: :bro:type:`bool` :bro:attr:`&redef` 
-================================================================ =
-
-
-Detailed Interface
-~~~~~~~~~~~~~~~~~~
-

doc/scripts/policy/protocols/dns/detect-external-names.bro.rst

@@ -1,26 +0,0 @@
-:tocdepth: 3
-
-policy/protocols/dns/detect-external-names.bro
-==============================================
-.. bro:namespace:: DNS
-
-This script detects names which are not within zones considered to be
-local but resolving to addresses considered local.  
-The :bro:id:`Site::local_zones` variable **must** be set appropriately for 
-this detection.
-
-:Namespace: DNS
-:Imports: :doc:`base/frameworks/notice </scripts/base/frameworks/notice/index>`, :doc:`base/utils/site.bro </scripts/base/utils/site.bro>`
-
-Summary
-~~~~~~~
-Redefinitions
-#############
-========================================== =
-:bro:type:`Notice::Type`: :bro:type:`enum` 
-========================================== =
-
-
-Detailed Interface
-~~~~~~~~~~~~~~~~~~
-