Fix type capture for raw html parser

examples/document/data/simple/document.json

@@ -4,6 +4,10 @@
     {
       "type": "data",
       "name": "body"
+    },
+    {
+      "type": "data",
+      "name": "footer"
     }
   ]
 }

snark-html/src/jvmMain/kotlin/space/kscience/snark/html/SnarkHtmlReader.kt

@@ -14,7 +14,7 @@ public interface SnarkHtmlReader : SnarkReader<PageFragment>{
 }
 
 public object RawHtmlReader : SnarkHtmlReader {
-    override val inputContentTypes: Set<String> = setOf("html")
+    override val inputContentTypes: Set<String> = setOf("text/html", "html")
 
     override fun readFrom(source: String): PageFragment = PageFragment {
         div {