Collection of fixes and improvements (#516)

docs/frontend/custom-ui/creating-custom-panels.md

@@ -26,7 +26,7 @@ The Home Assistant user interface is currently served to browsers in modern Java
 
 If you do need to run with ES5 support, you will need to load the ES5 custom elements adapter before defining your element:
 
-```js
+```javascript
 window.loadES5Adapter().then(function() {
   customElements.define('my-panel', MyCustomPanel)
 });

docs/frontend/custom-ui/lovelace-custom-card.md

@@ -91,6 +91,7 @@ In our example card we defined a card with the tag `content-card-example` (see l
 Add a resource to your Lovelace config with URL `/local/content-card-example.js` and type `module`.
 
 You can then use your card in your Lovelace configuration:
+
 ```yaml
 # Example Lovelace configuration
 views:
@@ -281,7 +282,6 @@ window.customCards.push({
 });
 ```
 
-
 ## Recommended Design Elements
 
 We are currently migrating from using Paper Elements to MWC (Material Web Component) Elements.