Merge pull request #15794 from damienalexandre/french-doc

[Doc] Fix french analyzer elision token filter doc

docs/reference/analysis/analyzers/lang-analyzer.asciidoc

@@ -621,11 +621,13 @@ The `french` analyzer could be reimplemented as a `custom` analyzer as follows:
     "analysis": {
       "filter": {
         "french_elision": {
-        "type":         "elision",
-            "articles": [ "l", "m", "t", "qu", "n", "s",
-                          "j", "d", "c", "jusqu", "quoiqu",
-                          "lorsqu", "puisqu"
-                        ]
+          "type":         "elision",
+          "articles_case": true,
+            "articles": [ 
+              "l", "m", "t", "qu", "n", "s",
+              "j", "d", "c", "jusqu", "quoiqu", 
+              "lorsqu", "puisqu" 
+            ]
         },
         "french_stop": {
           "type":       "stop",