DEV: remove deprecated discourse-search-banner (#63)

This updates the description of the theme. Also,

* transitions to a more light-weight `.webp` file type (~61% size reduction for `.png`, and ~35% for `.jpg`)
* enhances description to be more specific and fine-grained

As the part of the deprecation work of Advanced Search Banner theme component: https://meta.discourse.org/t/379322.

Author: Yuriy Kurant

.github/images/advanced-search.jpg

@@ -2,39 +2,54 @@
 
 A modern theme for Discourse with a hint of mint.
 
-## ⚙️ Configuration
+## ⚙️ Theme configuration
 
-### Discourse Settings
+Change the following settings for this theme to render properly.
 
-Following setting changes are required for this theme to render properly:
+### Edit Theme
 
-- `top menu` needs to be set to **category, latest, new, unread, top**
-- `desktop category page style` needs to be set to **Boxes with Subcategories**
+Go to **Admin > Themes & components** (`/admin/config/customize/themes`) page to edit Mint theme.
 
-### Discourse Search Banner
+- in **Dark color palette** dropdown select `mint-dark`
 
-In the options for the `discourse-search-banner` theme component, following changes are required for this theme to render properly:
+  ![theme dark color palette](/images/theme-dark-color-palette.webp)
 
-- `show-on` options needs to be set to **homepage**
-- ~~`plugin-outlet` options needs to be set to **below-site-header**~~
-    > As of Oct. 4th, 2022: The outlet will be auto-set by the Mint theme
-- `background image` can be set as per your requirement
+### Interface & layout
+
+Go to **Admin > Interface & layout** (`/admin/config/interface`) page.
+
+- **Top menu** needs to be set to `categories, latest, new, unread, top`
+- **Desktop category page style** needs to be set to `Boxes with Subcategories`
+
+   ![interface and layout](images/interface-and-layout.webp)
+
+### Welcome Banner
+
+Go to **Admin > Welcome banner** (`/admin/config/welcome-banner`) page.
+
+- in **Enabled on themes...** dropdown select `Mint Theme`
+
+  ![welcome banner themes](images/welcome-banner-enable.webp)
+
+- in **Page visibility** dropdown select `Homepage only`
+- in **Location** dropdown select `Below site header`
+
+  ![welcome banner settings](images/welcome-banner-settings.webp)
 
 ## 🖼️ Screenshots
 
 ### Homepage (categories)
 
-![main](.github/images/main.jpg)
-![categories](.github/images/categories.jpg)
+![main](images/main.webp)
+![categories](images/categories.webp)
 
 ### Latest
 
-![main](.github/images/topic-list.jpg)
+![topic list](images/topic-list.webp)
 
 ### Topic
 
-![main](.github/images/topic.jpg)
-
+![topic](images/topic.webp)
 ### Advanced Search
 
-![main](.github/images/advanced-search.jpg)
+![advanced search](images/advanced-search.webp)

.github/images/categories.jpg

@@ -1,5 +1,6 @@
 {
   "name": "Mint Theme",
+  "authors": "Discourse",
   "about_url": "https://meta.discourse.org/t/mint-a-modern-theme-for-discourse/202822",
   "license_url": "https://github.com/discourse/discourse-mint-theme/blob/main/LICENSE",
   "color_schemes": {
@@ -23,6 +24,5 @@
       "hover": "1c302b"
     }
   },
-  "components": ["https://github.com/discourse/discourse-search-banner.git"],
-  "screenshots": ["screenshots/light.png", "screenshots/dark.png"]
+  "screenshots": ["screenshots/light.webp", "screenshots/dark.webp"]
 }