[Rule Tuning] Tag Categorization Updates (#380)

* Add new categorization tags

* Change updated_date to 2020/10/26

Co-authored-by: Ross Wolf <31489089+rw-access@users.noreply.github.com>, @bm11100

rules/linux/linux_process_started_in_temp_directory.toml

@@ -2,7 +2,7 @@
 creation_date = "2020/02/18"
 ecs_version = ["1.6.0"]
 maturity = "production"
-updated_date = "2020/08/03"
+updated_date = "2020/10/26"
 
 [rule]
 author = ["Elastic"]
@@ -21,7 +21,7 @@ name = "Unusual Process Execution - Temp"
 risk_score = 47
 rule_id = "df959768-b0c9-4d45-988c-5606a2be8e5a"
 severity = "medium"
-tags = ["Elastic", "Linux"]
+tags = ["Elastic", "Host", "Linux", "Threat Detection"]
 type = "query"
 
 query = '''