docs: Fix Link in README.md

[1Maxnet1]

Summary:

While the former link provided only a 404 page, now one gets to the MobilityData site

Expected behavior:

When I click the link in the Readme.md I get to the Homepage of MobilityData

I did not run any unit tests or the like, as it is just a link in the Readme.md

• Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).

[welcome]

Thanks for opening this pull request! You're awesome. We use semantic commit messages to streamline the release process. Before your pull request can be merged, you should update your pull request title to start with a semantic prefix. Examples of titles with semantic prefixes:

• fix: Bug with ssl network connections + Java module permissions.
• feat: Initial support for multiple @PrimaryKey annotations.
• docs: update RELEASE.md with new process
  To get this PR to the finish line, please do the following:
• Read our Contribution Guidelines
• Follow Google Java style coding standards
• Include tests when adding/changing behavior
• Include screenshots

[CLAassistant]

All committers have signed the CLA.

[davidgamez]

LGTM!

[welcome]

🥳 Congrats on getting your first pull request merged!