Update screenshots and descriptions in Asset Library docs (#10665)

* doc: update support level and screenshots in Asset Library docs

community/asset_library/using_assetlib.rst

@@ -21,19 +21,18 @@ AssetLib - at the moment, it's empty, as we are not logged in.
 Searching
 ~~~~~~~~~
 
-In the center is the **search bar + settings** section, and the **assets** section
-below it - this lets you filter out certain kinds of assets based on a host
-of criteria. These include the asset **category** (such as 2D tools, scripts
-and demos), **engine version** they are intended for, **sorting order** (by
-update date, by name, etc.) and **support level**.
+In the left sidebar is the **search bar + settings** section, and the
+**assets** section takes up the main content area on the right. Below
+the search bar, you can filter assets by **category** (such as 2D tools,
+scripts and demos), **support level**, **engine version**, and **license**.
+You can also change the **sorting order** to sort by license, name, or
+update date.
 
 While most other filter settings should be fairly self-explanatory, it's worth
 going over what "support level" means in the Asset Library.
 Currently there are three support levels, and each asset can belong to only one.
 
-**Official** assets are created and maintained by the official Godot Engine
-developers. Currently, these include the official engine demos, which showcase
-how various areas of the engine work.
+**Featured** assets are hand-picked resources recognized for their value to the community.
 
 **Community** assets are submitted and maintained by the members of the
 Godot community.
@@ -184,13 +183,13 @@ elsewhere (such as downloading them directly from the AssetLib web frontend),
 which will take you through the same package installation procedure as with the
 assets downloaded directly via Godot that we just covered.
 
-.. |image0| image:: img/assetlib_website.png
-.. |image1| image:: img/assetlib_search.png
-.. |image2| image:: img/assetlib_asset.png
-.. |image3| image:: img/assetlib_register-login.png
-.. |image4| image:: img/assetlib_register.png
-.. |image5| image:: img/assetlib_login.png
-.. |image6| image:: img/assetlib_login_header.png
+.. |image0| image:: img/assetlib_website.webp
+.. |image1| image:: img/assetlib_search.webp
+.. |image2| image:: img/assetlib_asset.webp
+.. |image3| image:: img/assetlib_register-login.webp
+.. |image4| image:: img/assetlib_register.webp
+.. |image5| image:: img/assetlib_login.webp
+.. |image6| image:: img/assetlib_login_header.webp
 .. |image7| image:: img/assetlib_editor_workspace.png
 .. |image8| image:: img/assetlib_editor.png
 .. |image9| image:: img/assetlib_editor_asset.png