publish and update docs

[csells]

CHANGELOG.md

• gemini 2.0 updates
• smoke test update
• disabling attachments and voice notes
• unfocus for mobile

flutter pub publish a new version

• bump the version
• request publication of new version

README.md

• link to AI Toolkit docs
• configuring access to the network:
  - macOS: [Release|DebugProfile].entitlements:

            <plist version="1.0">
               	<dict>
              		...
              		<key>com.apple.security.network.client</key>
              		<true/>
               	</dict>
            </plist>

    - Android: `AndroidManifest.xml`:

            <manifest xmlns:android="http://schemas.android.com/apk/res/android">
                ...
                <uses-permission android:name="android.permission.INTERNET"/>
            </manifest>

docs.flutter.dev/ai-toolkit

• gemini 2.0 updates
• disabling attachments and voice notes
• CANCEL & ERROR
• configuring access to the network

[csells]

submitted as flutter/website#11870

[csells]

fixed with flutter/website#11870