[WAF] Add File Upload Anomaly Score Threshold effects (#25859)

Clarify the impact of file uploads on the OWASP Anomaly Score Threshold and false positives.

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Co-authored-by: Pedro Sousa <[email protected]>

Author: SomeBadCoding

src/content/docs/waf/managed-rules/reference/owasp-core-ruleset/concepts.mdx

@@ -37,4 +37,8 @@ The available score thresholds are the following:
 - _Medium – 40 and higher_ (default value)
 - _High – 25 and higher_
 
-Each threshold (_Low_, _Medium_, and _High_) has an associated value (_60_, _40_, and _25_, respectively). Configuring a _Low_ threshold means that more rules will have to match the current request for the WAF to apply the configured ruleset action. For an example, refer to [OWASP evaluation example](/waf/managed-rules/reference/owasp-core-ruleset/example/).
+Each threshold (_Low_, _Medium_, and _High_) has an associated value (_60_, _40_, and _25_, respectively). Configuring a _Low_ threshold means that more rules will have to match the current request for the WAF to apply the configured ruleset action. 
+
+When the OWASP Anomaly Score Threshold is set to _High_, file uploads may trigger the `949110: Inbound Anomaly Score Exceeded` rule due to the lower amount of scoring rules needed. Consider adjusting the threshold level, [adjusting individual rules](/waf/managed-rules/deploy-zone-dashboard/#configure-a-single-rule-in-a-managed-ruleset) in the ruleset, or [creating an exception](/waf/managed-rules/waf-exceptions/) if excessive false positives occur.
+
+For an example, refer to [OWASP evaluation example](/waf/managed-rules/reference/owasp-core-ruleset/example/).