nondestructive hash setting

spike/review/reinvent/ezmded/server/todo.yaml

@@ -0,0 +1,5 @@
+todo:
+- preview default via q param
+- css
+done:
+- https://developer.mozilla.org/en-US/docs/Web/API/History/pushState#change_a_query_parameter

spike/review/reinvent/ezmded/ui/index.html

@@ -189,8 +189,14 @@
             lastNavigateToQuery = new Date()
             const url = new URL(window.location)
             url.searchParams.set(k, v)
-            window.location.hash = "#?"+k+"="+v
-            //window.history.pushState({}, '', url)
+            var hash = "#?"
+            const it = url.searchParams.entries()
+            let result = it.next()
+            while (!result.done) {
+               hash = hash + result.value[0] + "=" + result.value[1] + "&"
+               result = it.next()
+            }
+            window.location.hash = hash
          }
 
          window.onhashchange = () => {