Updated user model

[AllieGie]

Updates Made:

• Added validation errors for User schema (first and last name at /post-signup)
• Updated User model
• added changes for the signup.ejs form

Things to note:

• there are a few incoming changes that are out of date on this merge.
  • For ex. the module.exports = mongoose.model('About', AboutSchema). This export doesn't exist on my latest
    version. Will see this change on the next commit.
• For now, I just want to be able to pull the changes everyone has made on the CSS and else where, before I keep working on the signup ejs/ css.

[pan-alex]

All changes up until the last commit look good. The most recent commit introduces a breaking change in signup.ejs because the data was split into two different forms. This causes an error anytime someone tries to sign up as data like the email, username, and password aren't included in the request.

Since the last commit is mostly for styling I would suggest reverting that commit so that we can merge this PR. Then add the styling changes in a new branch. You should be able to revert that commit by running: git reset --hard d1bb0d1