Add timeline_id to detection rules (#95)

* Adds timeline_id to all network rules
- Uses the ID for the 'Generic Network Timeline' from Elastic
* Adds timeline_id to all endpoint rules
- Uses the ID for the 'Generic Endpoint Timeline' from Elastic
* Adds timeline_id to all process-oriented rules
    - Uses the ID for the 'Generic Process Timeline' from Elastic
* Ran tests and toml-lint
* Bumped 'updated_date'

rules/windows/execution_script_executing_powershell.toml

@@ -2,7 +2,7 @@
 creation_date = "2020/02/18"
 ecs_version = ["1.6.0"]
 maturity = "production"
-updated_date = "2020/10/26"
+updated_date = "2020/10/27"
 
 [rule]
 author = ["Elastic"]
@@ -19,6 +19,7 @@ risk_score = 21
 rule_id = "f545ff26-3c94-4fd0-bd33-3c7f95a3a0fc"
 severity = "low"
 tags = ["Elastic", "Host", "Windows", "Threat Detection", "Execution"]
+timeline_id = "76e52245-7519-4251-91ab-262fb1a1728c"
 type = "query"
 
 query = '''