fix default timeout value (#1940)

Author: khorne3

docs/kb/rules/rule-file-perf-principles.md

@@ -43,9 +43,9 @@ files affects scan time more negatively than adding more SCCs.
 The time for matching is **number of files * time to match each file**. The time
 to check each file can also grow, in the worst case, exponentially, especially
 when a rule has a lot of matches in subpatterns. However, the default settings
-of `--timeout 30` `--timeout-threshold 3` means that a file times out if:
+of `--timeout 5` `--timeout-threshold 3` means that a file times out if:
 
-* 30 seconds elapse without the match process completing
+* 5 seconds elapse without the match process completing
 * 3 rules time out
 
 You can configure these flags to skip long files after a shorter timeout period