Fix descriptions for Visit <page> links

[atsansone]

From https://buganizer.corp.google.com/issues/337104253

Observed Results

Navigating through the page specifically on Visit links, listen that all of them are announced the same description.

• Screencast VoiceOver
• Screencast ChromeVox

Expected Results

Ensure that Visit links should have a descriptive name to users example

• Visit accessibility site link.
• Visit Animation and Motion link...

User Impact

Screen reader and Cognitive users are affected because all "Visit" links have the same description and are confused to them.

Steps to Reproduce

1. Enabled VoiceOver using Command + F5 also ChromeVox using Ctrl + Alt + Z
2. Open the following page: https://docs.flutter.dev/ui/widgets
3. Continue the linear navigation using the Tab key and reach the cards components.
4. Navigate through the links specifically on Visit links and listen to the results.

GAR Assessment

Flutter Docs

GAR Details

1.1. Do all non-text content and user interface components have meaningful accessible names and alternative text?

Environment Details

Machine: MAC/ChromeBook
Browser: Chrome Version 120.0.6099.272 (Official Build) (64-bit)
Screen reader: VoiceOver / ChromeVox.
Bug filling time: 15 mins.