Add Client Side validation

[bhskr44]

For this milestone of your portfolio website, you will implement a client-side validation of the data in the contact form before submission.

Project requirements

• You need to implement a simple validation:
  • The content of the email field has to be in lower case.
• You should implement the following interactions:
  • When the user submits the form, you check if the email is in lower case.
  • If the validation is OK, the form is sent.
  • If the validation is not OK, you show an error message to the user near the submit button informing them of the error and the form is not sent.