weblink parameters name and icon optional (#7199)

* weblink parameters `name` and `icon` optional

This will coincide with https://github.com/home-assistant/home-assistant-polymer/pull/1898

* 🚑 Fixes build error

source/_lovelace/entities.markdown

@@ -124,18 +124,20 @@ type:
   required: true
   description: weblink
   type: string
-name:
-  required: true
-  description: Link label.
-  type: string
-icon:
-  required: true
-  description: "Icon to display (e.g., `mdi:home`)"
-  type: string
 url:
   required: true
   description: "Website URL (or internal URL e.g. `/hassio/dashboard` or `/panel_custom_name`)"
   type: string
+name:
+  required: false
+  description: Link label
+  type: string
+  default: url path
+icon:
+  required: false
+  description: "Icon to display (e.g., `mdi:home`)"
+  type: string
+  default: "`mdi:link`"
 {% endconfiguration %}
 
 ## {% linkable_title Example %}