Update package README files to point to new repo

[bjankord]

Description of Issue

The README inside of packages/terra-component/docs/ and the README in packages/terra-component/, there are references to the old repos.

These files include the following lines:

- [Download the latest version](https://github.com/cerner/terra-arrange/archive/master.zip)
- Clone the repo: `git clone https://github.com/cerner/terra-arrange.git`

These need to be updated to the following:

- [Download the latest version](https://github.com/cerner/terra-ui/archive/master.zip)
- Clone the repo: `git clone https://github.com/cerner/terra-ui.git`

• terra-arrange
• terra-button
• terra-grid

TODO:
Add other repos we need to do this for to checklist.

[bjankord]

Do we still want people to clone the repo to use packages or should we direct people to use releases on npm? @Matt-Butler @mjhenkes

[Matt-Butler]

I'm fine if we want to leave

- Clone the repo: `git clone https://github.com/cerner/terra-ui.git`

in the root readme. I don't think it belongs in every package.

[bjankord]

This has now been resolved.