fix: invalid instruction for URL format entry (resolves #2170)

[jobara]

Resolves #2170

Updates the instructions to remove the schemeless URL example (e.g. example.com), as this format will fail validation.

Prerequisites

If this PR changes PHP code or dependencies:

• [x] I've run composer format and fixed any code formatting issues.
• [x] I've run composer analyze and addressed any static analysis issues.
• [x] I've run php artisan test and ensured that all tests pass.
• [x] I've run composer localize to update localization source files and committed any changes.

If this PR changes CSS or JavaScript code or dependencies:

• [ ] I've run npm run lint and fixed any linting issues.
• [ ] I've run npm run build and ensured that CSS and JavaScript assets can be compiled.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 97.93%. Comparing base (0d86ed2) to head (5aa84c4).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #2171 +/- ## ========================================= Coverage 97.93% 97.93% Complexity 2147 2147 ========================================= Files 333 333 Lines 9799 9799 ========================================= Hits 9597 9597 Misses 202 202 ```

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