Provide basic experimental formatter which supports invalid XML

See eclipse-lemminx/lemminx#1195

Signed-off-by: azerr <[email protected]>

package.json

@@ -225,6 +225,43 @@
           "markdownDescription": "Enable/disable ability to format document. Default is `true`.",
           "scope": "window"
         },
+        "xml.format.experimental": {
+          "type": "boolean",
+          "default": false,
+          "markdownDescription": "Enable/disable experimental formatter. Default is `false`.",
+          "scope": "window"
+        },
+        "xml.format.maxLineWidth": {
+          "type": "integer",
+          "default": 80,
+          "markdownDescription": "Max line width. Default is `80`.",
+          "scope": "window"
+        },
+        "xml.format.grammarAwareFormatting": {
+          "type": "boolean",
+          "default": true,
+          "markdownDescription": "Use Schema/DTD grammar information while formatting. Default is `true`.",
+          "scope": "window"
+        },
+        "xml.preferences.preserveSpace": {
+          "type": "array",
+          "default": [
+            "xsl:text",
+            "xsl:comment",
+            "xsl:processing-instruction",
+            "literallayout",
+            "programlisting",
+            "screen",
+            "synopsis",
+            "pre",
+            "xd:pre"
+          ],
+          "items": {
+            "type": "string"
+          },
+          "markdownDescription": "Element name for preserve spaces",
+          "scope": "window"
+        },
         "xml.format.emptyElements": {
           "type": "string",
           "enum": [
@@ -578,4 +615,4 @@
       }
     ]
   }
-}
+}