set advancing date

rfcs/text/0008-threat-intel.md

@@ -2,7 +2,7 @@
 <!-- Leave this ID at 0000. The ECS team will assign a unique, contiguous RFC number upon merging the initial stage of this RFC. -->
 
 - Stage: **1 (draft)** <!-- Update to reflect target stage. See https://elastic.github.io/ecs/stages.html -->
-- Date: **2020-11-09** <!-- The ECS team sets this date at merge time. This is the date of the latest stage advancement. -->
+- Date: **2021-02-17** <!-- The ECS team sets this date at merge time. This is the date of the latest stage advancement. -->
 
 Elastic Security Solution will be adding the capability to ingest, process and utilize threat intelligence information for increasing detection coverage and helping analysts make quicker investigation decisions. Threat intelligence can be collected from a number of sources with a variety of structured and semi-structured data representations. This makes threat intelligence an ideal candidate for ECS mappings. Threat intelligence data will require ECS mappings to normalize it and make it usable in our security solution. This RFC is focused on identifying new field sets and values that need to be created for threat intelligence data. Existing ECS field reuse will be prioritized where possible. If new fields are required we will utilize [STIX Cyber Observable data model](https://docs.oasis-open.org/cti/stix/v2.1/cs01/stix-v2.1-cs01.html#_mlbmudhl16lr) as guidance.