Add flask-only UI elements (MetaMask#941)

- New markdown admonition `:::flaskOnly` creates a block with Flask branding colors explaining that the section is Flask-only
- New `flask_only` custom prop for sidebar items adds a "Flask" tag to the sidebar item with appropriate colors

docusaurus.config.js

@@ -78,6 +78,21 @@ const config = {
         remarkPlugins: [
           require("remark-docusaurus-tabs"),
         ],
+        admonitions: {
+          tag: ":::",
+          keywords: [
+            "info",
+            "success",
+            "danger",
+            "note",
+            "tip",
+            "warning",
+            "important",
+            "caution",
+            "security",
+            "flaskOnly",
+          ],
+        },
       }),
     ],
     [

snaps-sidebar.js

@@ -84,6 +84,9 @@ const sidebar = {
             type: "doc",
             id: "reference/keyring-api/index",
           },
+          customProps: {
+            flask_only: true,
+          },
           items: require("./snaps/reference/keyring-api/typedoc-sidebar.cjs"),
         },
       ],

snaps/concepts/keyring-api.md

@@ -1,13 +1,13 @@
 ---
 description: Learn about the Snaps Keyring API.
 sidebar_position: 6
+sidebar_custom_props:
+  flask_only: true
 ---
 
 # About the Keyring API
 
-:::caution important
-This API is only available in [MetaMask Flask](../get-started/install-flask.md), the canary
-distribution of MetaMask.
+:::flaskOnly
 :::
 
 :::tip API documentation

snaps/how-to/use-keyring-api.md

@@ -2,10 +2,16 @@
 description: Use the KeyringSnapRpcClient from a dapp.
 sidebar_label: Use the Keyring API
 sidebar_position: 5
+sidebar_custom_props:
+  flask_only: true
 ---
 
 # Use the Keyring API from a dapp
 
+:::flaskOnly
+:::
+
+
 Your dapp can use the [Keyring API](../concepts/keyring-api.md) to interact with custom EVM accounts.
 Use the [`KeyringSnapRpcClient`](../reference/keyring-api/classes/KeyringSnapRpcClient.md)
 of the Keyring API to invoke Keyring RPC methods on your [Keyring snap](../concepts/keyring-api.md#terminology).

snaps/tutorials/custom-evm-accounts.md

@@ -1,15 +1,15 @@
 ---
 description: Create a Keyring snap to connect to custom EVM accounts in MetaMask.
+sidebar_custom_props:
+  flask_only: true
 ---
 
 # Create a snap to connect to custom EVM accounts
 
 This tutorial walks you through creating a snap that uses the [Keyring API](../concepts/keyring-api.md)
 to integrate custom EVM accounts in MetaMask.
 
-:::caution important
-The [Keyring API methods](../reference/keyring-api/index.md) mentioned in this tutorial are only
-available in [MetaMask Flask](../get-started/install-flask.md), the canary distribution of MetaMask.
+:::flaskOnly
 :::
 
 ## Prerequisites