Add USPTO Trademark to README

[pentium10]

• My submission is formatted according to the guidelines in the contributing guide
• My addition is ordered alphabetically
• My submission has a useful description
• The description does not have more than 100 characters
• The description does not end with punctuation
• Each table column is padded with one space on either side
• I have searched the repository for any relevant issues or pull requests
• Any category I am creating has the minimum requirement of 3 items
• All changes have been squashed into a single commit

[pentium10]

Opening a pull request will trigger a build to check the validity of all links in the project. After the build completes, please ensure that the build has passed. If the build did not pass, please view the build logs and correct any errors that were found in your contribution.

@marcelscruz the guide says we should fix the build, but I don't know what is wrong here

[Salozar73]

@pentium10 By the way, you can still sign up at api-hub.pro if you're not there yet.