Removed material-ui from project

[tylerconstance]

Creating a draft PR for code review and comments on this recipe.
This removes material-ui and several styles from the project to get closer to an unstyled version.

There are a few open questions I want to answer before I consider this good to go:

• Should we include a default or commented-out theme? We added a theme with an example color object
• Should we re-introduce the GlobalStyles component? Re-introduced normalize styles and an example of a body style
• Should we remove all css from this branch, or keep some in as a means of example usage? Kept a few examples
• Should I remove the package-lock from this branch? Poof💨, gone

[devinivy]

Here are my opinions on the matter.

• Should we include a default or commented-out theme?

  I think we should include an empty theme for styled components, but not a MUI theme.

• Should we re-introduce the GlobalStyles component?

  I would recommend using the normalize() styles from polished. After some research, that's how I left things before introducing MUI.

• Should we remove all css from this branch, or keep some in as a means of example usage?

  I would recommend keeping some examples of styled components.

• Should I remove the package-lock from this branch?

  I would recommend that we do remove it. We don't include it on the main branch, for one.
  But also, here was my thought last time it came up Version 2 #234 (comment):

  I was hoping to omit a package-lock from the repository, if that's cool! I still think projects should utilize one, but I also think it makes sense to have a completely fresh installation with the latest patch versions of everything upon starting a new project.

[tylerconstance]

I think we should include an empty theme for styled components, but not a MUI theme.

Should we provide any structure to what that theme should look like? And should it be a separate file, or just a variable or something on internals in this file?

[devinivy]

IMO it doesn't need any structure, but it should be in a separate file. What do you think?

[tylerconstance]

I may swap this for a more generic name like "primary" or "secondary," similar to how we did this with the material-ui theme in the material branch

[tylerconstance]

Closing since the purpose of this draft PR wasn't to merge into a branch, but to be reviewed as a standalone branch.