Fix FP S6582 (prefer-optional-chain): Update description and severity

sonar-plugin/javascript-checks/src/main/resources/org/sonar/l10n/javascript/rules/javascript/S6582.html

@@ -5,22 +5,22 @@ <h2>Why is this an issue?</h2>
 <p>This rule flags logical operations that can be safely replaced with the <code>?.</code> optional chaining operator.</p>
 <h2>How to fix it</h2>
 <p>Replace with <code>?.</code> optional chaining the logical expression that checks for <code>null</code>/<code>undefined</code> before accessing the
-property of an object.</p>
+property of an object, the element of an array, or calling a function.</p>
 <h3>Code examples</h3>
 <h4>Noncompliant code example</h4>
 <pre data-diff-id="1" data-diff-type="noncompliant">
-function foo(param) {
-    if (param &amp;&amp; param.value) {
-        bar(param.value);
-    }
+function foo(obj, arr, fn) {
+    if (obj &amp;&amp; obj.value) {}
+    if (arr &amp;&amp; arr[0])    {}
+    if (fn &amp;&amp; fn(42))     {}
 }
 </pre>
 <h4>Compliant solution</h4>
 <pre data-diff-id="1" data-diff-type="compliant">
-function foo(param) {
-    if (param?.value) {
-        bar(param.value);
-    }
+function foo(obj, arr, fn) {
+    if (obj?.value) {}
+    if (arr?.[0])   {}
+    if (fn?.(42))   {}
 }
 </pre>
 <h2>Resources</h2>

sonar-plugin/javascript-checks/src/main/resources/org/sonar/l10n/javascript/rules/javascript/S6582.json

@@ -13,7 +13,7 @@
     "constantCost": "5min"
   },
   "tags": [],
-  "defaultSeverity": "Major",
+  "defaultSeverity": "Minor",
   "ruleSpecification": "RSPEC-6582",
   "sqKey": "S6582",
   "scope": "All",