Add Example to SAST Rule Set Overrides

Add additional information on Overriding predefined
rules of SAST analyzers. This makes it easier to
verify which rule is being overwritten.

doc/user/application_security/sast/index.md

@@ -315,7 +315,6 @@ To disable analyzer rules:
 1. In one or more `ruleset.identifier` sub sections, list the rules that you want disabled. Every `ruleset.identifier` section has:
 
 - a `type` field, to name the predefined rule identifier that the targeted analyzer uses.
-
 - a `value` field, to name the rule to be disabled.
 
 ##### Example: Disable predefined rules of SAST analyzers
@@ -345,6 +344,9 @@ and `sobelow` by matching the `type` and `value` of identifiers:
       value = "sql_injection"
 ```
 
+Those vulnerabilities containing the provided type and value are now disabled, meaning
+they won't be displayed in Merge Request nor the Vulnerability Report.
+
 #### Override predefined analyzer rules
 
 To override analyzer rules:
@@ -365,30 +367,40 @@ To override analyzer rules:
 
 ##### Example: Override predefined rules of SAST analyzers
 
-In the following example, rules from `eslint`
-and `gosec` are matched by the `type` and `value` of identifiers and
-then overridden:
+Before adding a ruleset, we verify which vulnerability will be overwritten by viewing the [`gl-sast-report.json`](#reports-json-format):
+
+```json
+"identifiers": [
+        {
+          "type": "gosec_rule_id",
+          "name": "Gosec Rule ID G307",
+          "value": "G307"
+        },
+        {
+          "type": "CWE",
+          "name": "CWE-703",
+          "value": "703",
+          "url": "https://cwe.mitre.org/data/definitions/703.html"
+        }
+      ]
+```
+
+In the following example, rules from `gosec` are matched by the `type`
+and `value` of identifiers and then overridden:
 
 ```toml
-[eslint]
-  [[eslint.ruleset]]
-    [eslint.ruleset.identifier]
-      type = "eslint_rule_id"
-      value = "security/detect-object-injection"
-    [eslint.ruleset.override]
-      description = "OVERRIDDEN description"
-      message = "OVERRIDDEN message"
-      name = "OVERRIDDEN name"
-      severity = "Critical"
 [gosec]
   [[gosec.ruleset]]
     [gosec.ruleset.identifier]
         type = "CWE"
-        value = "CWE-79"
+        value = "703"
     [gosec.ruleset.override]
       severity = "Critical"
 ```
 
+If a vulnerability is found with a type `CWE` with a value of `703` then
+the vulnerability severity is overwritten to `Critical`. 
+
 #### Synthesize a custom configuration
 
 To create a custom configuration, you can use passthrough chains.